SPST Dr. Mi Qixi’s group reported their new progress in lead-free perovskite materials in a paper entitled “Band Alignment Boosts Charge–Carrier Collection in Sn-Based Perovskite over Pb Counterparts,” published in the Journal of Physical Chemistry Letters and was highlighted as a cover illustration.
The group previously discovered that CsSnBr3 (cesium tin bromide) has excellent semiconductor properties as a new lead-free perovskite material (http://www.shanghaitech.edu.cn/2018/0903/c1006a33693/page.htm). This work further fabricated CsSnBr3 into an optoelectronic device. By both theoretical calculations and experimental measurements of the valence band maximum of CsSnBr3, the researchers selected a charge-carrier transport material with a matched energy level, and obtained a photodetector that responds to the entire visible spectrum without applying an external bias. The performance of this photodetector exceeded the corresponding lead-containing semiconductor materials. These research results indicate that interface engineering is key to the device fabrication of CsSnBr3, and that any potential material defects can be overcome. The successful fabrication of the CsSnBr3 photodetector also lays a foundation for making this material into solar cells.
The authors of this paper are Li Binghan (sixth-year PhD student, first author), Long Ruiying (third-year MSc student, first author), Yao Qishun (second-year MSc student), Zhu Zihao (first-year MSc student), and Dr. Mi Qixi (corresponding author). ShanghaiTech University is the first responsible institution. The experimental measurement and theoretical calculation work in this paper has been assisted by Dr. Cheng Peihong and Dr. Yu Na of the Analytical Instrumentation Center of SPST, and by graduate students Shi Zhifang and Wei Qi.
Cover illustration in Journal of Physical Chemistry Letters.
Research team from left: Long Ruiying, Li Binghan, Prof. Mi Qixi, Zhu Zihao, Yao Qishun.