To reduce the size of optoelectronic devices, it is essential to understand the crystal size effect on the carrier transport through microscale materials. Here, we show a soft contact method to probe the properties of irregularly shaped microscale perovskite crystals by employing a movable liquid metal electrode to form a self-adaptative deformable electrode-perovskite-electrode junction. Accordingly, we demonstrate that (1) the photocurrents of perovskite quantum dot films and microplatelets show profound differences regarding both the on/off ratio and the response time upon light illumination; and (2) small-size perovskite (<50 μm) junctions may show negative differential resistance (NDR) behavior, whereas the NDR phenomenon is absent in large-size perovskite junctions within the same bias regime. Our studies provide a method for studying arbitrary-shaped crystals without mechanical damage, assisting the understanding of the photogenerated carriers transport through microscale crystals.
Bibliographical noteFunding Information:
We thank Prof. Jingshan Luo, Prof. Weihua Wang, and Prof. Weichao Wang for fruitful discussion. We acknowledge the financial support from the National Natural Science Foundation of China (91950116, 61571242, 11804170, 61775105, 61874167, 11504270), National Key R&D Program of China (Grant 2018YFB1500105), National Creative Research Laboratory program (Grant 2012026372) through the National Research Foundation of Korea, Natural Science Foundation of Tianjin City (19JCZDJC31000, 19JCJQJC60900, 17JCYBJC41400), and the 111 Project (B16027), the International Cooperation Base (2016D01025).
© 2020 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering