Controlling the Fermi level of semiconductors underlies most electronic and photovoltaic technologies. However, it remains limited to continuously tune the doping levels of the intensively studied lead halide perovskite by introducing any impurities or functional molecules. Here, we report a nonchemical charge transfer doping approach for continuous tuning of the work function (WF) of perovskite. A modification of surface WF from 4.18 to 5.05 eV is achieved by applying a bias voltage and varying its polarity on the formamidinium lead triiodide (FAPbI3) perovskite films via the top Au electrode acting as a medium. Here, n- and p-type charge transfer doping are realized by the negative and positive applied voltages, respectively. The negative applied voltage enhances both carrier mobility and density, leading to an improved conductivity of FAPbI3. The n-type FAPbI3 formed by the applied voltage of -2 V is applied to a dynamic perovskite/spiro-MeOTAD triboelectric device, which results in 1.5 and 3 times increases in DC voltage and current, respectively, as compared to the pristine perovskite without charge transfer doping. This tunable WF by the nonchemical charge transfer doping gives insights into innovational exploitation of the halide perovskite and also provides a new strategy for optoelectronics.
|Number of pages||8|
|Journal||ACS Energy Letters|
|Publication status||Published - 2021 Aug 13|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Ministry of Science and ICT (MSIT) of Korea under contracts NRF-2021R1A3B1076723 (Research Leader Program) and NRF-2016M3D1A1027663 and NRF-2016M3D1A1027664 (Future Materials Discovery Program). We thank the Pohang Accelerator Laboratory (PAL, Korea), Y.-S. Jeon (SKKU), and Y.-J. Park (SKKU) for the extended X-ray absorption fine structure (EXAFS) measurements. We thank the S.-H. Lee (SKKU) for the AFM measurements.
© 2021 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Chemistry (miscellaneous)
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Materials Chemistry