Perovskite solar cells are rapidly emerging in the field of new photovoltaic technology because of their simple preparation, low cost and high efficiency. Perovskite solar cells can be divided into formal and trans structures according to the device structure, compared to formal structures. The trans-structure device is simpler in preparation process, can form a film at a low temperature, has no obvious hysteresis effect, and is suitable for combining with a conventional solar cell (silicon-based battery, copper indium gallium selenide, etc.) to prepare a laminated device, and is subject to academia and industry. Concerns of the world. However, there are still application bottlenecks such as large difference between open circuit voltage and theoretical value, and low photoelectric conversion efficiency.
With the support of the National Science Research Program of Nano Research, Zhu Rui, a researcher at Peking University, and an academician and collaborator, conducted research on the bottleneck of trans-structured perovskite solar cells in terms of photoelectric conversion efficiency. The salt-assisted secondary growth method has pioneered the regulation of the characteristics of the perovskite thin film semiconductor, significantly reducing the energy loss of the non-radiative composite in the device, and has made a breakthrough in improving the open circuit voltage of the device, for the first time in the trans-structure device. A high open circuit voltage of more than 1.21V is obtained. At the same time, the photoelectric conversion efficiency of the trans-structured perovskite battery is significantly improved without losing the performance parameters such as photocurrent and fill factor, and the highest efficiency in the laboratory is 21.51%. With the certification of China Institute of Metrology, the photoelectric conversion efficiency of the device is as high as 20.90%, which is the highest record of the efficiency of trans-structured perovskite solar cell devices.
The result provides a new idea for improving the efficiency of trans-perovskite solar cell devices and promoting the application of such new types of photovoltaic devices, which can be further extended to perovskite-stacked solar cells and perovskite light-emitting devices. Application prospects and business value. Relevant results were published online in the journal Science on June 29.