Fabrication And Photoelectric Properties Of Doped Hydrogenated Nanocrustalline Silicon Thin Films

N-type phosphorus-doped hydrogenated nanocrystalline silicon (nc-Si(P):H) and p-type boron-doped hydrogenated nanocrystalline silicon (nc-Si(B):H) thin films were deposited on glass substrate by conventional radio frequency plasma enhanced chemical vapor deposition (rf-PECVD) through changing the process parameters such as the doping concentration, substrate temperature, concentration of SiH4, using SiH4and H2as reaction gas sources, PH3and B2H6as dopant diluted by H2. The films thickness was measured by Alpha step apparatus. Microstructure, chemical compositions and photoelectric properties were characterized and analyzed by the Raman, Fourier infrared absorption spectrum (FTIR) spectrometer,ultraviolet visible near infrared spectrophotometer (UV-VIS NIR), Hall and semiconductor tester. Thin films were studied at different reaction parameters on grain size, crystallization rate, deposition rate, the optical band gap and conductivity. The results indicated that nc-Si(P):H and nc-Si(B):H thin films with better performance can be prepared when PH3concentration was1%and B2H6concentration was0.2%, ensuring that substrate temperature was250℃, the rf power was60W and SiH4concentration was1.5%. Finally, the solar cells of ITO/p(n-Si:H)/I (nc-Si:H)/n (nc-Si:H)/Al structure type were fabricated and analyzed using above experimental parameters with a different group of intrinsic layer thickness, fixing thickness of p type and n type layers at20nm. The results showed that the better photovoltaic properties can be obtained when intrinsic layer thickness was400nm.