Crystallization Of Amorphous Silicon Film And Annealing Of Doped Copper Oxide Film

Aluminum induced cystalization （AIC） of amorphous silicon （a-Si） film to preparation polycrystalline silicon （p-Si） thin film is one of effective means to reduce cost of silicon solar cell. Copper oxide （CuO） has the advantages of cheap, and non-pollution, and abundance, and its optical bandgap matches with the solar spectrum, and so on, becoming an important photovoltaic materials. Doping of CuO is expected to improve its properties. In this dissertation, we investigated the AIC a-Si thin films and the properties of the Li doped CuO film at different annealing conditions.nc-Si thin films prepared by AIC a-Si was studied on structural and optical properties at different annealing temperatures from 200 to 500℃. Results showed that the crystal quality was improved as annealing temperature increases, and the maximal increase of transmittance reached 58% with annealing temperature increases. The interference peaks shift red-moved and optical bandgap reduced as annealing temperature increases. The optical bandgap reduces to 1.45 eV when annealing temperature was 500℃.We prepared Li doped CuO thin films by pulsed laser deposition （PLD） technique and studied the structural, electrical, and optical properties at different annealing conditions under nitrogen atmosphere. The results show that when the annealing temperature changed from 500℃ to 800℃, the crystallization of Li doped CuO thin films was improved and grain size became largger as annealing temperature increases. The conductive type of Li doped CuO thin films changes from n-type to p-type after annealed. Carrier concentration increases at first then decreases, mobility showed a trend of decrease and resisitivity reduces as annealing temperature increases. The optical band gap change slightly. When the annealing time changed from 0.5 h to 2 h, the crystallinity changed better. The results show that the Li doped CuO thin films annealing at 600℃ with 1 h under nitrogen atmosphere have best electrical property, its carrier concentration is 48.1×1017cm^-3, mobility is 0.43×10^-2 cm²V^-1s^-1, resisitivity is 38.1 Ω·cm. The optical band gap is 1.51 eV.The properties of Li doped CuO thin films annealed in oxygen atmosphere were investigated. The results show that when the annealing temperature changed from 500 to 800℃, the crystallization and grain size of Li doped CuO thin films was improved as annealing temperature increases. Grain refinement was happened deu to appearing recrystallization at 800℃. The conductive type changes from n-type to p-type after annealing. Carrier concentration increases at first then decreases, the mobility showed a little change, and the resisitivity reduced as annealing temperature increases. The optical band gap essentially unchanged. When the annealing time changed from 0.5 to 2 h, the structural property improved. The research show that the Li doped CuO thin films annealing at 600℃ for 1 h under oxygen atmosphere have best electrical property, its carrier concentration is 60.17×1017 cm^-3, mobility is 0.322×10^-2 cm²V^-1s^-1, resisitivity is 9.3Ω·cm. The optical band gap is 1.49 eV.