Study Of Structue And Properties Of P-doping Amorphous Silicon Thin Film By PECVD

Due to its low cost, simple fabrication technology and short energy-pay time etc, amorphous silicon thin-film solar cell is receiving tremendous attention recently. The solar cell could be divided into superstrate configuration (p-i-n) and substrate configuration (n-i-p) based on different substrates and deposition order. The internal electric field of silicon solar cell is built synergetically by p and n layers, which directly affect the open circuit voltage (Voc) and short-circuit current density (Jsc) of the cell.So n layer plays an important on the cell performance as well.N-typed hydrogenated amorphous silicon films were fabricated by plasma radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) with SiH4 and PH3 of high hydrogen dilution acting as reactive gas and dopant gas respectively. Effects of phosphorus dopant concentration, discharge power and temperature of substrates on the optical and electirical properties of thin films were studied. The structure of films was characterized by X-ray diffraction (XRD) and Raman scattering spectrum. The transtance of films was measured by UV-vis spectrophotometer, refractive index and extinction coefficient were stimulated by NKD-7000W System Spectrophotometer and dark conductivity of the films was measured by high electrometer.The results show that the silicon films deposited in different parameters are all amorphous; as the doping concentration goes up, the value of refractive index reach the peak at the doping concentration R=0.8%; and extinction coefficient constantly increases; what's more, the surface roughness is generally not affected by the doping concentration. When discharge power grows, refractive index of a-Si:H firstly increases and then drops, peaking at the power of 70W; the maximum value of dark conductivity of films is 9.32×10-3 S/cm at 100W. With the temperature of substrates varying from 60 to 300℃, dark conductivity firstly increases and then drops, and reaches its optimal value of 1.88×10-2S/cm at 200℃.