This book contains the papers presented at the international symposium Polycrys­ talline Semiconductors - Grain Boundaries and Interfaces (POLYSE '88) that was held in Malente, FRG, from August 29 to September 2, 1988. This conference has two roots: Firstly, it is a successor to a conference on polycrystalline semi­ conductors held in Perpignan, France, in 1982 and to a summer school in Erice, Italy, in 1984. Secondly, it continues a series of German workshops on polycrys­ talline semiconductors, which have been organized every year since 1983 by two of the present editors (H. P. S. and J. H. W. ) in Stuttgart, FRG. As in these previ­ ous workshops, the symposium POLYSE '88 also tried to bridge the gap between fundamental research and technological aspects of polycrystalline semiconductors with emphasis on physical properties. In order to realize this conception, 12 scientists recognized in their fields were invited to give reviews of their respective work. The expert presentations of these scientists complemented by all other contributions, including an ad hoc evening workshop on the chemical analysis of grain boundaries by scanning tunneling microscopy, resulted in a lively and rewarding symposium. We would particularly like to thank the invited speakers for their talks, as well as for undertaking the task of refereeing the submitted papers. These speakers are: L. N. Aleksandrov Y. Ishida P. Pirouz A. Bourret J. D. Joannopoulos H. W. Schock H. Cerva L. L. Kazmerski H. Teichler F. Greuter S. Martinuzzi K. N.

I Grain Boundary Structure.- Intergranular Total Energy Maps and the Structure of a Grain Boundary.- Grain Boundary Structure Determination by HREM: A Comparison with Computer Relaxed Configurations for Pure Tilt in Germanium.- Multiple Structures of a [001] ? = 13 Tilt Grain Boundary in Germanium.- Computer Modelling of Grain Boundaries by Use of Interatomic Potentials.- Transmission of Dislocations with Non-common Burgers Vectors Through ? = 9 (12?2) Boundaries in Silicon and Germanium Observed by In Situ HVEM.- II Grain Boundary Chemistry and Electronic Properties.- High Resolution Electron Microscopy of the Structure and Chemistry of Grain Boundaries and Other Interfaces in Semiconductors.- Theoretical Studies of the Impurity Segregation and Electrical Properties of Polycrystalline Silicon by LCAO Electronic Theory.- Electronic Properties of ? = 25 Silicon Bicrystals by Deep Level Transient Spectroscopy.- The Influence of Structure and Impurity Precipitation on the Electrical Properties of the Grain Boundaries in Silicon: Copper Precipitation in the ? = 25 Boundary.- EBIC Contrast and Precipitation in ? = 13 and ? = 25 Annealed Silicon Bicrystals.- Electron Beam Induced Current Contrast and Transmission Electron Microscopy Analysis of Special Grain Boundaries in Silicon.- SEM-EBIC Investigations of the Electrical Activity of Grain Boundaries in Germanium.- III Segregation, Activation and Passivation.- Atomic-Level Imaging and Microanalysis of Grain Boundaries in Polycrystalline Semiconductors.- Investigation of the Cobalt Segregation at Grain Boundaries in Silicon.- On the Influence of the Cottrell Atmosphere on the Recombination Losses at Grain Boundaries in Polycrystalline Silicon.- Hydrogen Passivation of Grain Boundaries in Silicon Sheet Material.-Atomic Hydrogen Passivation Studies of Microcrystalline Phases in Ion-Implant Damaged Surface Layers of Silicon.- Hydrogen Injection and Migration in Silicon.- Analysis of the Polycrystalline Semiconducting Film Electrical Resistance Variation Due to Isothermal Desorption and Temperature Stimulated Desorption of Oxygen.- IV Segregation, Activation and Passivation.- Activation and Passivation of Grain Boundary Recombination Activity in Polycrystalline Silicon.- Thermal Activation and Hydrogen Passivation of Grain Boundaries.- Analysis of Metal-Doped Polycrystalline Silicon with Secondary Ion Mass Spectrometry.- Oxygen Detection in Polycrystalline Silicon.- Generation of Radiation Defects in the Vicinity of Twin Boundaries in EFG Silicon Ribbons.- Physical Properties of Polycrystalline S-Web Si Ribbons.- Grain Boundary Structure in S-WEB Silicon Ribbon.- Characterization of MBE-Grown Polysilicon.- V Technology.- Mechanisms of Epitaxial Growth of Polar Semiconductors on (001) Silicon.- Preparation and Characterization of Nickel Silicide.- Characterization of the Interface of Silicon pn-Junctions, Fabricated by the Silicon Direct Bonding (SDB) Method.- Metal and Polycrystalline Silicon Reactions.- Interfacial Reactions of TiNx/Si Contacts.- Linear and Parabolic Growth Kinetics in Binary Couples.- VI Thin Films.- Polycrystalline Compound Semiconductor Thin Films in Solar Cells.- Electronic Properties of Photoetched CdSe Films.- Thin Film Transistors and Light Sensors with Polycrystalline CdSe-Semiconductors.- VII Crystallization.- Crystallization Processes and Structures of Semiconductor Films.- Crystallized Silicon Films for Active Devices.- Laser Recrystallization of Polysilicon for Improved Device Quality.- Growth of Sb-Doped Epitaxial Si Layers Through Recrystallizationof Poly-Si on a (100) Si Substrate.- VIII Transport Properties.- Current Control by Electrically Active Grain Boundaries.- Numerical Modelling of the Intergranular Potential Barrier Height and Carrier Concentration in Polysilicon.- Hall Mobility and Carrier Concentration of e-Gun Evaporated Poly-Si Films.- Measurement and Calculation of the Carrier Concentration in Polycrystalline Germanium Thin Films.- Grain Boundary States in Float-Zone Silicon Bicrystals.- Pressure Studies of Metastable Electron Traps in Grain Boundaries of p-HgMnTe and p-HgCdMnTe.- Band Tailing in Polycrystalline and Disordered Silicon.- IX Thin Films.- Microstructure and Interfaces of Polysilicon in Integrated Circuits.- Effect of the Grain Boundaries in Small Grain Polysilicon Thin Film Transistors.- Kink Effect in the Double-Gate Accumulation-Mode N-Channel Polysilicon Thin-Film Transistors.- Applications of Poly-Si in Selective-Area and Three-Dimensional Devices.- Thin-Film Transistors from Evaporated Low Temperature Processed Poly-Si Films.- Pressure Effect on In Situ Boron-Doped LPCVD Silicon Films.- Index of Contributors.