Chinese Journal of Quantum Electronics ›› 2019, Vol. 36 ›› Issue (6): 705-708.

• Laser Tech. and Devices • Previous Articles     Next Articles

Preparation of stable and efficient mixed-halide perovskite based light emitting diodes

FAN Weisheng1,2, LI Xinhua1   

  1. 1 Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China;
     2 University of Science and Technology of China, Hefei 230026, China

  • Received:2019-03-28 Revised:2019-04-10 Published:2019-11-28 Online:2019-11-19

Abstract: It is a remarkable advantage of organic−inorganic hybrid perovskite to tune their bandgap by adjusting the stoichiometric ratio of halide. It is critical to their applications in tandem solar cells, wavelength-tunable light emitting diodes (LEDs) and laser. However, illumination or applied bias will cause the phase separation of mixed-halide perovskite, and results in formation of iodide-rich domains, reduction of photovoltaic devices open-circuit voltage. The emission wavelength of luminous LED is pinned to the infrared region. The phase separation is suppressed by halide redistribution by self-assembled long-chain organic ammonium capping layers at nanometer-sized grain surfaces. The LED with stable emission wavelength is obtained, and its external quantum efficiency is improved to 2%.

Key words: light emitting diodes, mixed-halide perovskite, halide migration, phase separation

CLC Number: