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-structure according to the structure of the device. Compared with the formal structure, the trans-structure device is simpler in preparation process, can form film at low temperature, has no obvious hysteresis effect, and is suitable for traditional solar energy. Batteries (silicon-based batteries, copper-indium-gallium-selenium, etc.) have attracted the attention of academics and industry in combination with the advantages of preparing laminated devices. However, there are still application bottlenecks such as large gap between open circuit voltage and theoretical value, and low photoelectric conversion efficiency. .
Supported by the National Scientific Research Program of Nano Research (2015CB932200, Basic Research on Perovskite Solar Cells), Researcher Zhu Rui of Peking University, Academician Gong Qihuang and collaborators conducted research on trans-structured perovskite solar cells In the bottleneck of photoelectric conversion efficiency, the method of 'salt-assisted secondary growth' was proposed, which artificially realized the regulation of the characteristics of perovskite thin-film semiconductors, and significantly reduced the energy loss of non-radiative recombination in the device. A breakthrough was made in the open circuit voltage. For the first time, a high open circuit voltage of 1.21V (material bandgap width ~1.6eV) was obtained in the trans-structured device.
At the same time, without changing the performance parameters such as photocurrent and fill factor, the photoelectric conversion efficiency of the trans-structured perovskite battery is significantly improved—the highest laboratory efficiency is 21.51%. Approved by China Institute of Metrology, the device The photoelectric conversion efficiency is as high as 20.90%, which is the highest record of the current trans-structured perovskite solar cell device efficiency.
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.
