Characteristic Analysis of HfO2 Thin Films Deposited by PE-ALD and its Application in Solar Cells

• Main Authors: ZHANG, XIAO-YING, 張小英
• Other Authors: LIEN, SHUI-YANG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/x9kgj2

博士 === 大葉大學 === 電機工程學系 === 105 === HfO2 thin films were grown by plasma enhanced atomic layer deposited (PE-ALD) and their deposition condition is optimized. Changing different pretreatment silicon substrates and annealing temperatures improved the passivation properties of HfO2 thin films on silicon. HfO2 thin films used in high-efficiency n-type Si solar cells were also investigated. The main works are summarized as follows: 1. The condition of HfO2 thin films deposited by PE-ALD was optimized. When the silicon substrate was pretreated by O2 plasma, the HfO2 thin films have the best passivation effect on silicon comparing to N2 plasma pretreatment and non-pretreatment. A mechanism of O2 plasma pretreatment silicon substrates improving passivation properties of HfO2 thin films on silicon was also present. 2. Post annealing in N2 ambient of HfO2 thin films were carried out to investigate their passivation effect on the silicon. The results showed that rapid thermal annealing at 500 ℃ for 10 min yielded a highest lifetime of 67 μs. The surface recombination velocity (SRV) is 187 cm/s. A mechanism of post annealing improving passivation properties of HfO2 thin films on silicon was also investigated. 3. The effect of different SRV on n-type silicon solar cells was simulated by PC1D. Simulation results showed that the efficiency could reach 20.5% while the front SRV is 22 cm/s and the rear SRV is 187 cm/s.