The efficiency of halide perovskite solar cells has progressed rapidly through a series of major breakthroughs. Currently, a certified efficiency of 25.2% has been achieved for a solar cell using a polycrystalline thin film. This is the result of having reached 75% of the Shockley–Queisser limit for single-junction solar cells. However, for further improvements, new breakthrough technologies are required. This article reviews the impact of previous breakthrough technologies on the efficiency of halide perovskite solar cells, based on certified efficiencies. We clarify the current status of halide perovskite solar cells and introduce photon recycling as the next technological innovation for higher efficiencies. Photon recycling keeps the photon concentration inside the light-harvesting layer high, and consequently, leads to open-circuit voltages close to the theoretical value. Although photon recycling has not yet been implemented in real halide perovskite solar cells, three key technologies for implementing it are examined.

卤化物钙钛矿太阳能电池的效率通过一系列重大突破而迅速发展。目前，使用多晶薄膜的太阳能电池已达到25.2％的认证效率。这是因为单结太阳能电池已达到Shockley-Queisser限制的75％。但是，为了进一步改进，需要新的突破性技术。本文根据经过验证的效率，回顾了以前的突破性技术对卤化物钙钛矿太阳能电池效率的影响。我们阐明了卤化钙钛矿太阳能电池的现状，并介绍了光子回收技术，作为提高效率的下一项技术创新。光子回收可将光收集层内的光子浓度保持在较高水平，因此，导致开路电压接近理论值。尽管在真正的卤化物钙钛矿太阳能电池中尚未实现光子回收，但是研究了实现它的三种关键技术。