Properties and Crystallization of Amorphous Si1-xPx Alloy Thin Films

Abstract

ABSTRACTThe properties of amorphous Si1-xPx alloy thin films with 20–44 at.% P were studied. The results showed that these alloys have a wide bandgap Eo ranging from 1.5 to 2.15 eV, where the alloy films with 20 at.% P have the widest bandgap (1.75–1.82 eV) at annealing temperatures ≤600 °C. Conductivity measurements showed that two electron conduction processes mainly exist: hopping conduction in the band tail at low temperatures and extended-state conduction in the conduction band at high temperatures. Crystallization studies showed that the alloys are thermally stable and crystallize at temperatures between 850 and 1100 °C. A new phosphide, Si7P3 was formed by annealing the alloys with 30–44 at.% P at temperatures ≥950 °C depending on the P concentration.