A research team led by HAN Keli from Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences fabricated a sensitive photodetector based on lead-free perovskite single crystals. Their findings were published in The Journal of Physical Chemistry Letters.

Organ-lead perovskites have recently attracted broad attentions due to the excellent optoelectronics properties. For instance, the high performance photodetectors have been developed based on organo-perovskites.

However, the heavy metal Pb in lead-based perovskites is toxic to both humans and the environment which is often considered as a drawback. Thus, finding a stable, non-toxic and high performance perovskite is highly desirable.

Sb³⁺ based single crystals and the responsivity of the photodetector. (Image by YANG Bin)

“We have developed a high performance photodetector based on MA₃Sb₂I₉ microsingle crystals (MSCs), ” said Prof. HAN.

Scientists found that MA₃Sb₂I₉ single crystals exhibited a low trap-state density of ~10¹⁰ cm^-3, high carrier mobility of 12.8 cm² V^-1 s^-1 and long carrier diffusion length reaching 3.0 μm.

The responsivity of MA₃Sb₂I₉ single crystal photodetector can reach to 40 A/W for monochromatic light (460 nm).In addition, the photodetector shows fast response time (<1 ms), which corresponds to both high gain and gain-bandwidth product.

This work was supported by the key research project of National Natural Science Foundation. (Text by YANG Bin)