Green electro- and photoluminescence from nanocrystalline Si film prepared by continuous wave Ar+ laser annealing of heavily phosphorus doped hydrogenated amorphous silicon film

Abstract

A thin layer of plasma enhanced chemical vapor deposited (PECVD) heavily phosphorus doped hydrogenated amorphous silicon (a-Si:H) film was annealed by cw Ar+ laser scanning. Different from conventionally prepared polycrystalline Si films, it was found that nanocrystalline Si (nc-Si) was formed in our laser annealed sample. Room-temperature green electroluminescence (EL) peaked at 530 nm was achieved from our nc-Si film. Photoluminescence (PL) from the same sample also shows the 530 nm green peak, in addition to the red peak located at 680 nm. The film had a rather high electrical conductivity of 10S/cm as well. The light emitting and highly conductive nc-Si film provides a new possibility to fabricate optoelectronic devices along with the well-developed laser annealing techniques of a-Si:H.