科学家研制出光电转换效率超27%的钙钛矿太阳能电池

Core Insights - The efficiency of perovskite solar cells has significantly improved from an initial 3.8% to over 26% in the past decade, yet there remains a gap to the theoretical efficiency limit [1][2] - The research team from the Chinese Academy of Sciences has identified uneven chlorine distribution in perovskite films as a key issue affecting efficiency and stability [2] - A new strategy called Homogenized Vertical Chlorine Distribution (HVCD) has been developed to address this issue, leading to a perovskite solar cell prototype with a power conversion efficiency of 27.2% [3] Group 1 - The use of methylammonium chloride (MACl) has been common in the growth of perovskite films due to its ability to lower nucleation barriers and promote high-quality crystal growth [1] - The uneven chlorine distribution caused by rapid migration of chloride ions during crystallization leads to defects and electronic barriers, hindering carrier transport and efficiency [2] - The research findings have been published in the journal Science, highlighting the importance of addressing chlorine distribution for enhancing solar cell performance [2] Group 2 - The HVCD strategy involves introducing alkali metal oxalates during film growth, which helps to bind chlorine ions and achieve uniform distribution [3] - The resulting perovskite films exhibit a carrier lifetime of up to 20 microseconds and a low interface defect density of 10^13 per cubic centimeter [3] - The prototype solar cell maintained 86.3% of its initial efficiency after 1529 hours of operation under standard sunlight conditions, demonstrating significant stability [3]