Professor Raphael Tsu (with Tsu replaced by Zhu in pinyin) is a world leader in the areas of quantum properties of materials and device physics. An acknowledged authority in these subjects Professor Tsu has published nearly two hundred scholarly papers in scientific journals; an author of a monograph on  quantum wells and superlattice materials and devices [1] of which he is a co-inventor, holder of  several patents for his discoveries and invention. The description of his research contributions while at the IBM, T.J. Watson Research Center in Yorktown Heights was presented to the White House by the US Army Research Office, The Superlattice Story, played an important role in the 90’s towards the US National Nanoscience Initiative (NNI).

 Professor Tsu was born in a Catholic family in Shanghai, China. It is not generally known that the establishment of the Chinese Catholic Church in 1601 by Ricci, a Jesuit, was helped from within the Emperor’s court of the Ming Dynasty. As a child he was inspired by his great uncle who in 1926 was amongst the first six Chinese bishops ever to be consecrated at the Vatican in Rome and as a teenager by his US educated father Adrian and French educated uncle, Louis. His father side grandfather and great uncle were pioneers in power plant and modern shipyard in Shanghai. When he was leaving Shanghai, his great uncle, in his death bed told him to remember the old Chinese saying that to succeed needs the right tool. Raphael Tsu emigrated to the west, first  to study physics in England and later earned a PhD from Ohio State University. Professor Tsu built upon the progress in quantum mechanics made during the first half of the twentieth century into man-made quantum solids.

 After several years working as a member of the Technical Staff at the world famous Bell Laboratories (BTL) at Murray Hill, NJ, developing ultrasonic amplifier, a mechanism invented by Dr. D.L. White, Professor Tsu moved to the IBM, T.J. Watson Research Center in Yorktown Heights, NY as an associate to Dr. Leo Esaki, the inventor of Esaki diodes [2] and Physics Nobel laureate in 1973. That was the beginning of his well known collaboration with Esaki, working on the theory of man-made quantum materials, superlattices and quantum wells.   

 By his theoretical calculations Professor Tsu proved that the quantum states can be designed in multiple layers of semiconductors in a superlattice structure.  In comparison to the atomic size lattice constants of natural crystals, the periodic repeat distance in man-made devices can be much longer and hence the relevant reciprocal wave vector and crystal momentum are very small. He also provided the first quantum theoretical calculations of Negative Differential Conductance (NDC) in such artificial materials [3].

 Dr. Tsu’s theory required the fabrication of precise multi-layer semiconductor films. Such fabrication can only be achieved with ultra-high purity chemicals, heated to the vapor state and then allowing the vapor to condense on single crystal supporting bases known as substrates, while the entire assembly is held under extremely low gas pressure in very high vacuum. This process is repeated, alternating with vapors of different compositions until a superlattice with the desired thickness and number of atomic layers are produced. The initial rapid development of these new materials and devices [1] owes much to the professional competition between IBM and Bell telephone corporations.  These works lead to the discovery of zone-folding in energy-momentum for electrons [3] as well as for phonons [4], resonant tunneling [5,6], the famous Tsu - Esaki current density formula [5,7], and the tunneling time [8]. Returning from a year in Max Planck Institute, Stuttgart, under the Alexander von Humboldt Award, where Professor Tsu served to popularize superlattice and quantum wells in Europe and Germany, he was given a new assignment at IBM, to catch up with BTL in laser annealing, where the most perfect silicon was produced. It was during this phase of his career; he discovered that crystalline silicon may be amorphized by pulsed UV laser, [9] and teaming up with Dr. Jim Van Vecten to propose the non-thermal reordering with high power pulse laser. [10]

 Later Professor Tsu joined the Amorphous Semiconductors Institute (ASI) and directed energy research at Energy Conversion Devices (ECD) in MI near Detroit invited by the famous inventor Stan Ovshinsky. His contribution there included the first experimental determination of the volume fraction of crystallinity for conductivity percolation in amorphous silicon and Germanium [11], and providing experimental proof the existence of an intermediate order. [12] He discovered experimentally that post annealing with H₂ and even O₂ can drastically remove dangling bond defects in amorphous silicon.[13]      During 1985-1987 Professor Tsu was the amorphous silicon program group leader at the National Renewable Energy Laboratory (then known as SERI, Solar Energy Research Institute) at Golden, Co. His theoretical derivation of the relationship between the optical absorption and disorder in amorphous silicon and germanium in terms of fundamental constants shows that the slope of the famous Tauc plot is uniquely determined by the oscillator strength of the transition, the deformation potential and the mean deviation of the atomic coordinates obtained from the RDF. [14] Other important theory includes hopping conduction in superlattice [15], and Bloch oscillator [16] which became the highest THz oscillators.

 Dr. Tsu is currently holder of the position of Distinguished Professor of electrical engineering at the University of North Carolina at Charlotte. Early on at UNCC, he became the first to offer prove that quantum confinement plays an important role in porous silicon, [17] as well as providing the theory and experiment of a quantum step, instead of quantum well. [18] He teamed up with Prof. E. Nicollian and Q. Ye [19] in the earliest conductance measurements through silicon quantum dots, showing conductance peaks leading conductance steps, a many body effect which is only understood recently. [20] Other recent research interests of his include the theory of dielectric constant, capacitance and doping of a quantum dot [21] [22], [23]. Basically as size is reduced to nanometer regime, dielectric constant is drastically reduced, making doping almost impossible, and the capacitance can only be defined via energy because equal potentials for few electrons are meaningless in general. [24] This work led to extremely curious results, the difference in the total interaction energy of N electrons confined inside a sphere versus N contains features given by the periodic table of elements, the shell model of the atomic system. [25]

 He was also amongst the first to derive the quantum mechanical formula to calculate the impedance of a wave function and show that just as Maxwell’s electromagnetic waves experience 376.7 W free space impedance, the propagation of a quantum mechanical wave even in a perfectly phonon free, non-dissipative system involves a quantum wave impedance, QWI ~ Nh/e², where h is Planck’s constant, e the unit of electronic charge and N is an integer or a fractional number [26]. 

 In 1972, he organized a group and was invited by the Chinese Science Academy which resulted in the first report on the technology in China published in Scientific American. This led to his involvement through establishing the first Chinese Scientific delegation visit to the US, which was invited by the US-China Relations Committee of the US Academy of Science in November. During this visit, he worked with the US State Department for the program and logistics on the East Coast. This effort contributed to the opening of scientific exchange between United States and China.

 Professor Raphael Tsu is a fellow of the American Physical Society and member International Advisory Board of the Microelectronic Journal, Elsevier; winner of: Outstanding Contribution Award -IBM 1975; Alexander von Humboldt Award – 1975; Co-winner Am. Phys. Soc. International New Materials Prize – 1985

 

Reference

 

1. Applying the insight into superlattices and quantum wells for nanostructures: Low-dimensional structures and devices, Microelectronics J. 38, no.10-11, p.959-1012 Oct/Nov 2007.

2. New Phenomenon in narrow germanium p-n junctions, Phys. Rev. 109, 603 (1958).  

3. See  “Twenty years later, after the path breaking work of Esaki and Tsu on negative differential conductivity in superlattices, I realized that I had in fact anticipated their basic physics, albeit in a more primitive form: What was not possible in bulk semiconductors, appeared to become possible in superlattices with their much longer period” Herbert Kroemer in  http://nobelprize.org/nobelprizes/physics/laureates/2000/kroemer-autobio.html  See also L Esaki and R. Tsu, IBM J. Res. Develop. 14, 61 (1970).

4. Phonon and polariton modes in a superlattice, R. Tsu  and  S. S. Jha,  Appl. Phys. Lett. 20, 16 1972.

5. R. Tsu and L. Esaki, Appl. Phys Lett. 22, 562 (1973).

6. Resonant Tunneling in Semiconductor Double Barriers. L.L. Chang, L. Esaki and R. Tsu, Appl. Phys. Lett. 24, 593 (1974).

7. Quantum-mechanical tunneling time and its relation to the Tsu-Esaki formula, Marc M. Cahay , et al  Proceedings of SPIE 1675, 142 (1992).

8. Superlattice to Nanoelectronics, R. Tsu, (Elsevier 2005) Chapter 2.

9. Order-Disorder Transition in Single-Crystal Silicon by Pulsed UV Laser, R. Tsu, R. T. Hodgson, T. Y. Tan  and J. E.  Baglin, Phys. Rev. Lett.  42, 1356 (1979).

10. Nonthermal  Pulsed Laser Annealing of Si; Plasma Annealing, J. A. Van Vechten, R. Tsu and  F. W. Saris, Phys. Lett. 74A(6), 422 (1979).

11. Critical Volume Fraction of Crystallinity for Conductivity Percolation in P-doped Si:F:H   Alloys, R. Tsu, J. G. Hernandez, S. S. Chao, S. C. Lee and K. Tanaka, APL 40, 534 (1982).

12. Electroreflectance and Raman Investigation of Glow-Discharge Amorphous Si:F:H, R. Tsu, M. Isu, S. R. Ovshinsky and F. H. Pollak, Solid State Comm. 36, 817 (1980).

   14.  Optical Absorption and Disorder in Hydrogenated amorphous Si-Ge and Si-C Alloys systems, R. Tsu, P. Menna, and A.H. Mahan, Solar Cells, 21 189,(1987)

15. Hopping Conduction in a Superlattice, R. Tsu, and G. Dohler, Phys. Rev. B 12, 680, (1975).

16. Stark Quantization in  Superlattices, R. Tsu and L. Esaki, Phys. Rev. B 43, 5204 (1991).

17. Correlation of Raman and  PL Spectra of Porous Silcon, R. Tsu, H. Shen and M. Dutta, Appl. Phys. Lett. 60, 112 (1992).

18. Optical Properties of Quantum Steps, H. Shen, F. H. Pollak and R. Tsu, Appl. Phys. Lett.57,13(1990).

19. Resonant Tunneling Via Microcrystalline Silicon Quantum Confinement, Q. Y. Ye, R. Tsu and  E. H. Nicollian, Phys. Rev. B 44, 1806 (1991).

   20.  Revisiting tunneling via Si-quantum dots, R. Tsu, Microelectr. J.,2007, in press, doi:10.1016/j.mejo.2007.07.008.

21. A Simple Model For The Dielectric Constant Of Nanoscale Silicon Particle,  R. Tsu, D.Babic, and L.Ioriatti,J. Appl. Phys. 82, 1327(1997)

22. Ground State Energies of One-and Two-Electron Silicon Dots,D. Babic, R. Tsu and  R. F. Greene,  Phys. Rev. B 45, 14150 (1992).

23. Doping of a Quantum Dot, R. Tsu and D. Babic, Appl. Phys. Lett. 64, 1806 (1994).

24. Classical capacitance of few-electron dielectric spheres, J. Zhu, T.J. LaFave and R. Tsu,  Microelectronic J. 37, 1293 (2006)

   25.  Capacitance: A property of nanoscale materials based on spatial symmetry of
            discrete  electrons, T. LaFave Jr., and  R. Tsu, Microelectronics J. 38 11-12, 200726. Timir Datta & Raphael Tsu arXiv:cond-mat/0311479v1

            [cond-mat.mes-hall]                       

 

Selected areas of expertise

_____________________________________________________________

 

• Quantum Well
• Resonant Tunneling
• Negative Differential Conductance
• Superlattice
• Laser annealing
• Raman scattering and optical property in solids
• Quantum Wave Impedance
• Non-crystalline and Porous Semiconductors
• Classical Coulomb Correlation effects

 

Selected Bibliography

_____________________________________________________________

 

• Applying the insight into superlattices and quantum wells for nanostructures: Low-dimensional structures and devices, Microelectronics J. Vol 38, no.10-11, p.959-1012 Oct/Nov 2007
• Superlattice to Nanoelectronics, (Elsevier, 2006, ISBN 0 08 044377 X).
• Porous Silicon, Eds. Z.C. Feng and R. Tsu, (World Scientific, 1994, ISBN 981-02-1634-3)
• Nanostructured Electronics and Optoelectronics Materials, R. Tsu and Q. Zhang, pp.527-267, in Nanostructured Materials, Ed. by Carl C. Koch ( Noyes Publ, Norwich, NY 2002)

 

Selected List of Publications

 

3           Phonon Radiation by Uniformly Moving Charged Particles in Piezoelectric Solids, R. Tsu, J. Appl Phys. 35, 125 (1964).

4            Interaction of Optical and Acoustic Phonons with Longitudinal Plasma Waves, R. Tsu and D.L. White, Annals of Phys. 32, 100 (1965)

8           Landau Damping and Dispersion of Phonon and Photon in Polar Semiconductors, R. Tsu, Phys. Rev. 164, 380 (1967).

12         Superlattice and Negative Differential  Conductivity  in Semiconductors, L. Esaki and R. Tsu, IBM J. Res. Develop. 14, 61 (1970).

13         Luminescence Spectra of Eu-Chalcogenides, R. Tsu  and L Esaki, Phys. Rev. Let. 24, 455 (1970).

15         Electrical Transport Properities in a Superlattice, P. A. Lebwohl and R. Tsu, J. Appl. Phys. Lett. 41, 2664 (1970).

20           A One-Dimensional Superlattice in Semiconductors, L. Esaki, L. L. Chang and R. Tsu,  Proc. 12th Int. Conf. Low Temp. Phys. 551, Kyoto (1970).

21           Nonlinear Optical Response of Conduction Electrons in a Superlattice, R. Tsu and L. Esaki, Appl. Phys. Lett. 19, 246 (1971).

24         Disorder-Activated Acoustic Mode in Raman Spectrum of Ga_1-xAl_xAs, H. Kawamura, R. Tsu and L. Esaki, Phys. Rev. Lett. 29, 1397 (1972).

25         Phonon and Polariton Modes in a Superlattice, R. Tsu and S. S. Jha, Appl. Phys. Lett. 20, 16 (1972).

27         Tunneling in a Finite Superlattice, R. Tsu and L. Esaki, Appl. Phys. Lett. 22, 562 (1973).

28         Magnetic Quantization in a Superlattice, R. Tsu and J. Janak, Phys. Rev. B 9, 404 (1974).

29         Resonant Tunneling in Semiconductor Double Barriers. L.L. Chang, L. Esaki and R.Tsu, Appl. Phys. Lett. 24, 593 (1974).

30          Raman Scattering in the Depletion Region of GaAs, R. Tsu, H. Kawamura and L.Esaki,  Solid State Comm. 15, 321 (1974).

31          Optical Properties of a Semiconductor Superlattice, R. Tsu, A. Koma and L. Esaki, J. Appl. Phys. 46, 842 (1975).

32          Hopping Conduction in a Superlattice, R. Tsu, and G. Dohler, Phys. Rev. B 12, 680, (1975).

35         Effects of Quantum States on the Photocurent in a Superlattice, R. Tsu, L. L. Chang, G. Sai-Halasz  and L. Esaki, Phys. Rev.  Lett. 34, 1509 (1975).

40         Anti-Stokes Luminescence in Europium Monochalcogennides, R. Merlin, R. Tsu, G. Guntherodt, G. Abstreiter and M. Schafer, Solid State Comm.

              22, 609 (1977).

41          New Semiconductor Superlattice, G. Sai-Halasz, R. Tsu and L. Esaki, Appl. Phys.Lett. 30, 651(1977).

54         Order-Disorder Transition in Single-Crystal Silicon Induced by Pulsed UV Laser R. Tsu, R.T. Hodgson, T. Y. Tan  and J. E.  Baglin, Phys. Rev. Lett. 

              42,1356  (1979).

56          Reasons to Believe Pulsed Laser Annealing of Si Does Not Involve Simple Thermal Melting, J. A. Van Vechten, R. Tsu, F. W. Saris and

              D. Hoonhout, Phys. Lett. 74A(6), 417 (1979).

57          Non-Thermal Laser Induced Ordering and Plasma Life Time, R. Tsu and S. S. Jha, Journal de  Physique, C4,25 (1980).           

59          Electroreflectance and Raman Investigation of Glow-Discharge Amorphous Si:F:H, R.Tsu, M. Isu, S. R. Ovshinsky and F. H. Pollak, Solid State Comm.

              36, 817 (980).

61          Effects of quantitative disorder on the electronic structures of Si and Ge, Kazuyoshi Tanaka and Raphael Tsu, Phys. Rev. B 24, 2038 (1981).

62          Critical Volume Fraction of Crystallinity for Conductivity Percolation in P-doped Si:F:H Alloys, R. Tsu, J. G. Hernandez, S. S. Chao, S. C. Lee and

               K. Tanaka, APL  40, 534 (1982).

63           Material Characterization by Raman Scattering, R. Tsu, Proc. Photo-optical Instrumentation  Engr. 276, 78 (1981).

65           Temperature Dependence of Silicon Raman Lines, R. Tsu and J. G. Hernandez, Appl.Phys. Lett. 41,1016 (1982).

68           Ordering of Amorphous Germanium Prior to Crystallization, M. Paesler, D. Sayers, R. Tsu and J. G. Hernandez, Phys. Rev. B 28, 4550 (1983).

69           Raman Characterization of Semiconductors Revisited, F. H. Pollak and R. Tsu, SPIE Proc. 452, 26 ( 1983).

71           Structure Dependence of Conductivity Percolation in Ge-Films, J. G. Hernandez, D. Martin, S. S. Chao and R. Tsu, Appl. Phys. Lett. 44, 672 (1984).

76           Effects of Mean Free Path on the Quantum Well Structures of Amorphous Materials, R. Tsu, in Tetrahedrally-Bonded Amorphous Semiconductors,

               Edited by D. Adler and H. Fritzche, Plenum Press, N.Y., 433 (1985).

84           Structural Information from the Raman Spectrum of a-Si, D. Beeman, R. Tsu and M. F. Thorpe,  Phys. Rev. B 32 874 (1985).

93           Passivation of Dangling Bonds in Amorphous Silicon and Germanium by Gas Absorption, R. Tsu, D.  Martin, J. Hernandez and S. R. Ovshinsky, 

               Phys. Rev. B 35,2385 (1987). 

94             Structure Characterization of Amorphous Silicon and Germanium, R. Tsu in Disordered  Semiconductors, Plenum Publishing Corp., N.Y. 479 (1987).

103         Pssivation of Defects in Polycrystalline Superlattices and Quantum Wells Structures, R. Tsu, E. H. Nicollian and A. Reisman, Appl. Phys. Lett. 55, 1897 (1989).

105         Phonon Linewidth and Bond Angle Deviation in Amorphous Silicon and Germanium, R. Tsu, M. A. Paesler and D. Sayers, J. Non-Crystalline Solids

               114, 199 (1989).

106         Phase Coherenece and Damping in Amorphous Quantum Wells, R. Tsu, J. Non-Crystalline Solids 114 ,708 (1989).

109         Optical Properties of  Quantum Steps, H. Shen, F. H. Pollak and R. Tsu, Appl. Phys. Lett.57,13(1990).

112         Stark Quantization in  Superlattices, R. Tsu and L. Esaki, Phys. Rev. B 43, 5204 (1991).

113         Resonant Tunneling Via Microcrystalline Silicon Quantum Confinement, Q. Y. Ye, R. Tsu and  E. H. Nicollian, Phys. Rev. B 44, 1806 (1991)..

115         Correlation of Raman and Photoluminescence Spectra of Porous Silcon, R. Tsu, H. Shen and M. Dutta, Appl. Phys. Lett. 60, 112 (1992).

116         Microstructure of Visible Luminescent Porous Silicon, M. W. Cole, J. F. Harvey, R. A. Lux, D. W. Eckart and R. Tsu, Appl. Phys. Lett. 60, 2800 (1992).

117         High Pressure Optical Investigation of Porous Silicon, W. Zhou, H. Shen, J. F. Harvey, R. A. Lux, M. Dutta, F. Lu, C. H. Perry, R. Tsu, and F. Namavar, Appl.

               Phys. Lett. 61,1435 (1992).

118         Raman and Optical Characterization of Porous Silicon, J. F. Harvey, H. Shen, R. A. Lux, M. Dutta, J. PamuLapati and R. Tsu, Mat. Res. Soc. Symp.

               Proc. 256, 175 (1992)

119         Disordering in ⁶⁹GaAs/⁷¹GaAs Isotope Superlattice Structures, T. Y. Tan, H. M. You, S. Yu, U. M. Gosele, W. Jager, D. W. Boeringer, F. Zypman

               and R. Tsu, J. Appl. Phys. 72 , 5206 (1992). 

120         Ground State Energies of One-and Two-Electron Silicon Dots, D. Babic, R. Tsu and  R. F. Greene,  Phys. Rev. B 45, 14150 (1992).

121         Quantum Confinement Effects on the dielectric Constant of Porous Silicon, J. F. Harvey, R. A. Lux, D.C.Morton, G. F. McLane and R. Tsu, Mat.

               Res. Soc. Symp. Proc. 283, 437 (1993)

122         Optical Studies of Electroluminescence Structures from Porous Silicon, J. F. Harvey, R. A. Lux, D.C.Morton, G. F. McLane and R. Tsu, Mat. Res.

               Soc. Symp. Proc.283, 395 (1993)

123         Transport in Nanoscale Silicon Clusters, R. Tsu, Physica B 189, 235 (1993)

124         Field Induced Localization in Superlattices, Chapter 1, Semiconductor Interfaces Microstructure and Devices: Properties and Applications,

               (Edited by Z.C.Feng, IOP Publishing Ltd. Bristol England (1993)) p.3-19.

125         Electrical Properties of a Silicon Quantum Dot Diode, E.H.Nicollian and R. Tsu, J. Appl. Physics. 74, 4020 (1993)

126         Silicon  Quantum  Well with Strain-Layer Barrier, R. Tsu, Nature 364, 19 (1993).

127         Porous Silicon Electroluminescence Mechanisms and Defect Analysis, J. F. Harvey, E.H. Poindexter, D.C.Morton, R. A. Lux, and R. Tsu,

               in Optical Properties of Low Dimensional Silicon Structures, Eds. D.C.Benshal, L.T.Canham and S. Ossicini, (Kluwer Acad. Publishing 1993). P. 179.       

128         Effects of the Reduction of Dielectric Constant in Nanoscale Silicon, R. Tsu and D. Babic, in Optical Properties of Low  Dimensional Silicon Structures,

               Eds. D.C. Benshal, L.T.Canham and S. Ossicini, ( Kluwer Acad. Publishing 1993).p.203.

129         Doping of a Quantum Dot, R. Tsu and D. Babic, Appl. Phys. Lett. 64, 1806 (1994).

130         Cascading Electron, R. Tsu, Nature 369, 442 (1994)

131         Slow conductance oscillations in nanoscale silicon clusters of quantum dots, R. Tsu, X.L.Li and H.Nicollian, Appl. Phys. Lett. 65, 842 (1994)

132         Lateral Ohotovotaic Effect in Porous Silicon, D.W.Boeringer and R. Tsu, Appl. Phys. Lett.64, 2332 (1994)

133         Doping in Si Nanocrystallites, R. Tsu and D. Babic, in Porous Silicon, Ed. Z.C. Feng and R. Tsu, ( World Scientific 1994) p.41

134         Modeling the Multiplication of Conductance Structures in Clusters on Silicon Quantum Dots, D.W.Boeringer and R. Tsu, Mat. Res. Soc.

               Symp. Proc. 358, 569 (1995)

135         Visible Light Emission in Silicon-Interface Adsorbed Gas Superlattices, R. Tsu, J. Morais, and A. Bowhill, Mat. Res. Soc. Symp. Proc. 358, 825 (1995).

136         Avalanche Amplification of Resonant Tunneling through Parallel Silicon Microcrystallites, D.W.Boeringer and R. Tsu, Phys. Rev. B51, 13337,(1995)

137         Correlation of Raman and Optical studies with AFM in Porous Si, Adam A. Flilios, Susan S. Hefner, and Raphael Tsu, J. Vac.  Sci. & Tech.B14, 3431(1996)

138         Avalanche Amplification of Resonant Tunneling through Parallel  Silicon Microcrystallites,  D.W.Boeringer and R. Tsu, Phys. Rev. B51, 13337,(1995)

139         A Simple Model For The Dielectric Constant Of Nanoscale Silicon Particle,  R.  Tsu, D.Babic, and L.Ioriatti,J. Appl. Phys. 82, 1327(1997)

148         Exciton in Nanoscale Silicon Quantum Dots, D.Babic and R. Tsu, Superlattice and Microstructure, 22, 581(1997)

149         Determination of Activation Energy in Quantum Wells, J. Ding and R. Tsu, Appl. Phys. Lett. 71, 2124 (1998)

150         Visible Electroluminescence in Si/absorbed Gas Superlattice, R. Tsu, Q.Zhang, and A.Filios, SPIE 3290, 246, (1998).

151         Silicon Epitaxy on Si(100) with Adsorbed Oxygen, R. Tsu, A.Filios, C.Lofgren, K. Dovidenko, and  C.G.Wang, Electrochem. & Solid State Lett. 1, 80  (1998).

152.        Photovoltaic Effects, D. Boeringer and R. Tsu, in Encyclopedia of Electrical and Electronic Engineering, ed. J.G.Wester (John Wiley & Sons,  NY 1998).

153.        Room Temperature Silicon Quantum Devices, R. Tsu, in International  J. High Speed Electronics and Systems, editors:  M.Dutta and M. Stroscio,

               (World Sci, Singapore, 1998)

154.        R. Tsu, A. Filios, C. Lofgren, K.Dovidenko and  C. G. Wang, Electrochem and Solid State Lett., 1 (2) 80 (1999).

155.        R. Tsu, ECS Proc. 98-19, 3 (1999)

156.        R. Tsu, K. Dovidenko,  and  C. Lofgren, ECS Proc. 99-22, 294-301 (1999)

157.        R. Tsu and R.F.Greene, Inverse Nottingham Effect Cooling, Electrochem and Solid State Lett.2, 645 (1999)

158.        Ultra-stable Visible Electroluminescence from c-Si/O Superlattice, Q.Zhang, A.Filios, C Lofgren and R. Tsu, Physica-E 8, 365 (2000)

159         Phenomena in silicon nanostructure devices, R. Tsu, Appl. Phys. A 71 391-402, (2000)

160         Si based green ELD : Si – oxygen superlattice”, R. Tsu, Phys. Stat. Sol. 180, 333 (2000)

161         Cooling by Field Emission with Resonant Tunneling : Design Parameters, R. Tsu, Cold Cathod, ECS Proc. Vol 2000-28, 91 (2001)

162         Structure, Optical and Electronic Properties of Semiconductor-Atomic Superlattices, R. Tsu, J.C. Lofgren and O.Gurdal, Proc. 25^th Int. Conf. Phys. Semicond.,

               Osaka 2000, Eds. N.Miura and T. Ando, ( Springer-Verlag, Berlin Heidelberg 2001)  p.1613

163         Structure of MBE Grown Semiconductor-Atomic Superlattices, R. Tsu and   J.C.Lofgren, J. Crystal Growth, 227-228, 21 (2001)

164         Heterogeneity in Hydrogenated Si : Intermediate ordered chainliuke objects, David V. Tsu, B.S.Chao, S.R.Ovshinsky, S.J.Jones, J.Yang, S.Guha, and

               R. Tsu, Phys. Rev. B63, 125338 (2001)

165         Transport through a nine period Si/O Suparlattice, Y-J Seo, J.C.Lofgren and R. Tsu, Appl. Phys. Lett. 79 788 (2001)

166         Electronic and Optical Characteristics of Multilayer Nanocrystalline Silicon/Adsorbed Oxygen Suparlattice, Yong-Jin Seo, Raphael Tsu, Jpn J.

               Appl. Phys. 40, 4799(2001)

167         Challenges in Nanoelectronics, R. Tsu, Inst. Nanotechnology 12, 625(2001)

168         Nanostructured Electronics and Optoelectronic Materials, R. Tsu and Q. Zhang, in Nanostructured Materials, Ed. Carl C Koch,

               (Noyes Publ, Norwich, NY. 2002) pp527-567

169         Qtronics, R. Tsu, and T. Datta, Proc. 26^th ICPS, Edinburgh, IOP Publishing, Edinburgh, UK, July 29-Aug.2, 2002

170         Some Fundamental Issues for Heterojunctions – Multipole-electrode Hybrid Confinement, R. Tsu, Proc. ECS-2002 Centennial Philadelphia, May 12-17 2002 

171         Structure and Optoelectronic Properties of Si-O Superlattice, K. Dovidenko, J.C. Lofgren, F.de Freitas, Y.J.Seo and R. Tsu,

               Physica E: Low-dimensional Systems and Nanostructures, 2003

172         Challenges in the Implementation of Nanoelectronics, R. Tsu, in Special Issue of Microelectronics J. (Elsevier, 2003), LDSD-2002 Fortaleza,

               Brazil Dec. 8-13, 2002

173         Quantum Devices with Multipole-Electrode – Heterojunctions Hybride Structures, R. Tsu Adv. Semicond. Heterostructures, Eds. M. Stroscio and

               M. Dutta, (World Sci. Singapore)

174         Cooling by Inverse Nottingham Effect with Resonant Tunneling , Y. Yu, R.F.Greene, and R. Tsu, Adv. Semicond. Heterostructures, Eds.

               M. Stroscio and M. Dutta, (World Sci. 2003, Singapore) 

177         Challenges in the Implementation of Nanoelectronics,R.Tsu, Microelect. J.34, 329 2003

178         New type of field emitter, resonant tunneling electron emitter with a factor of 20 lower field: Electron emission through a multilayer planar nanostructured

               solid-state field-controlled  emitter, V. Semet, V.T. Binh, J.Zhang, J.Yang, M.A. Khan, and R. Tsu, APL. 84,1937 (2004) 

179         Size dependence saturation of PbS quantum dots , K. Kang, K. Daneshvar and R. Tsu Microelectronic J. 35, 629 (2004)

180         Stability Issues in Tunneling via Quantum systems, R. Tsu, Microelectronics J., 36, 212(2005)

181         Three-dimensional quantum dot array, K. Daneshvar, K. Kang and R. Tsu, Microelectronics J, 36, Issues 3-6, 250 (2005)

182         Classical capacitance of few-electron dielectric spheres, Jinwen Zhu, Tim LaFave, Jr. and Raphael Tsu, Microelectronics Journal, 37, 1293, (2006)

183         Silicon–O–M–O–silicon superlattice, R. Tsu, D. Quinlan and K. Daneshvar, Microelec J.37, Issue 12, 1519, (2006)

184         Interaction of CdSe/ZnS quantum dots: Among themselves and with matrices, K. Liu, T.A.  Schmedake, K. Daneshvar and R. Tsu, Microelectronics J. 38,

               Issues 6-7, 700 (2007) 

185         Revisiting tunneling via Si-quantum dots, R. Tsu, Microelectronics Journal, In Press, Corrected Proof, Available online 27 August 2007

186         Shaping electron field emission by ultrathin multilayered structure cathodes, V. Semet, Vu Thien Binh and R. Tsu, Microelectronics J, 

               In Press, Corrected  Proof, Available online 12 September 2007

187         Capacitance: A property of nanoscale materials based on spatial symmetry of discrete electrons, Tim LaFave Jr. and Raphael Tsu, Microelectronics Journal, 

               In Press, Corrected Proof, Available online 25 September 2007

188         Applying the insight into superlattices and quantum wells for nanostructures: Low-dimensional structures and devices, Raphael Tsu, Microelectronics Journal,
               Volume 38,  Issues 10-11, October-November 2007, Pages 959-1012