Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells

Chunfeng Lan; Jingting Luo; Huabin Lan; Bo Fan; Huanxin Peng; Jun Zhao; Huibin Sun; Zhuanghao Zheng; Guangxing Liang; Ping Fan

doi:10.3390/ma11030355

Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells

Materials (Basel). 2018 Feb 28;11(3):355. doi: 10.3390/ma11030355.

Authors

Chunfeng Lan^{1

2

3}, Jingting Luo^{4

5}, Huabin Lan^{6

7}, Bo Fan^{8

9}, Huanxin Peng^{10

11}, Jun Zhao^{12

13}, Huibin Sun^{14

15}, Zhuanghao Zheng^{16

17}, Guangxing Liang^{18

19}, Ping Fan^{20

21}

Affiliations

¹ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lanchunfeng@gmail.com.
² Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. lanchunfeng@gmail.com.
³ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lanchunfeng@gmail.com.
⁴ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. luojt@szu.edu.cn.
⁵ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. luojt@szu.edu.cn.
⁶ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lanhb420@163.com.
⁷ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lanhb420@163.com.
⁸ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. fanb07@hotmail.com.
⁹ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. fanb07@hotmail.com.
¹⁰ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. P2385284535@163.com.
¹¹ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. P2385284535@163.com.
¹² Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. zhaojun@szu.edu.cn.
¹³ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. zhaojun@szu.edu.cn.
¹⁴ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. hbsun@szu.edu.cn.
¹⁵ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. hbsun@szu.edu.cn.
¹⁶ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. zhengzh@szu.edu.cn.
¹⁷ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. zhengzh@szu.edu.cn.
¹⁸ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lgx@szu.edu.cn.
¹⁹ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. lgx@szu.edu.cn.
²⁰ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. fanping@szu.edu.cn.
²¹ Institute of Thin Film Physics and Applications, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China. fanping@szu.edu.cn.

Abstract

We provided a new method to improve the efficiency of Sb₂S₃ thin film solar cells. The TiO₂ electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb₂S₃ solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO₂ films. Compared with the undoped TiO₂, Li-doped mesoporous TiO₂ dramatically improved the photo-voltaic performance of the thermal-evaporated Sb₂S₃ thin film solar cells, with the average power conversion efficiency (PCE) increasing from 1.79% to 4.03%, as well as the improved open-voltage (V_oc), short-circuit current (J_sc) and fill factors. The best device based on Li-doped TiO₂ achieved a power conversion efficiency up to 4.42% as well as a V_oc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb₂S₃ solar cells. This study showed that Li-doping on TiO₂ can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb₂S₃-based solar cells.

Keywords: Li-doping; Sb2S3 solar cells; charge extraction; photovoltaic performance; thermal evaporation.