a-(Si,Ge):H alloys: status and issues

The authors report the findings of a workshop devoted to assessing the technical status of and identifying critical issues for future research on a-(Si,Ge):H alloy materials and devices. The workshop was attended by 28 participants representing industry, academic, and government laboratories. The technical status of a-(Si,Ge):H materials included electron and hole mobility-lifetime products, Urbach energies for conduction and valence band tails, hydrogen bonding, and midgap density-of-states. Critical needs that were identified included fabrication, analysis, and modeling of devices, reproducible and well-characterized deposition, and more complete structural, optical, and electrical characterization of device-quality materials