This award supports cooperative materials research in the applied physics of semiconductors to be conducted by William Paul of Harvard University and Ivan Chambouleyron of the University of Campinas in the state of Sao Paulo, Brazil. This work will involve a study of the fundamental properties of amorphous hydrogenated germanium, especially those important for photoelectronic applications. While a similar material, amorphous hydrogenated silicon is the usual material used for thin film solar cells and field-effect transistors, this research will seek more fundamental understanding of non- crystalline semiconductors made of hydrogenated silicon- germanium alloys and unalloyed amorphous hydrogenated germanium. This work will combine the efforts of two laboratories, each of which has special facilities. They will exchange samples, apply new research techniques and collaborate in the analysis of results to arrive at improved theories for the germanium materials and the alloys. Specific facilities at Harvard include glow discharge, photo-chemical vapor deposition and sputtering: those at Campinas, sputtering and reactive evaporation. Campinas has Mossbauer spectroscopy available while Harvard has special facilities for differential scanning calorimetry, gas evolution and time of flight measurements. Clearly, the facilities, experience and expertise of these two groups will complement each other and the collaboration will advance the scientific and device parameters of amorphous semiconductors.
