Synthetic Organic-Inorganic Hybrid Perovskite Single Crystal Materials by Xinjiang Institute of Physics and Chemistry, Chinese Academy of Sciences

At present, the mainstream of organic - inorganic hybrid perovskite solar cell device has two main structures, namely, porous structure and planar structure. In both of these structures, the organic-inorganic hybrid perovskite is based on polycrystalline nano-thin films whose photoelectric conversion efficiency has exceeded 20%. For the organic-inorganic hybrid perovskite system, the photoelectric properties of monocrystalline devices are far superior to the currently widely used nanocrystalline thin film devices. Mainly due to the reduction of the number of defects such as the grain boundaries in the single crystal sample, so that the probability that the photo-generated carriers reach the electrodes on both sides of the device greatly increases, thereby increasing the photocurrent density of the device.

Xu Jinbao, a researcher at Xinjiang Institute of Physics and Chemistry, Chinese Academy of Sciences, led his research team and found a simple and convenient method for preparing large-size single crystals of CH3NH3PbBr3. The method uses a single solvent precursor, the method is simple, the cost is low, all the steps can be completed at room temperature, and the use of the method to grow a large size 14 × 14mm crystal, the crystal phase structure, P-43m (215) Space group. The spontaneous polarization behavior of the single crystal in the dark state is weak. Under the light illumination, the crystal shows a spontaneous polarization phenomenon on the surface, which shows the characteristics of light-induced polarization. Under light and dark state, the surface The potential difference of up to 200mV, is conducive to the preparation of high open circuit voltage photoelectric conversion devices. The single-crystal surface current distribution is uniform, photocurrent is about 20 times the dark-state current, and no attenuation in the overall surface, the results show that monocrystalline hybrid perovskite devices compared with the current nanocrystalline thin film devices, is expected Greatly increase its photo-current density.

The research results were published in the Journal of Physical Chemistry Letters. The related research work was supported by the "Thousand Talents Program" - Xinjiang Special Fund, National Natural Science Foundation of China and CAS Western Light Project.

Single-crystal samples in the light and dark state surface potential data curve