钙钛矿太阳能电池中电子传输材料的研究进展

progress in electron-transport materials in application of perovskite solar cells

有机-无机杂化的卤素钙钛矿材料在2009年首次应用在光伏器件中,而后有关此类型太阳能电池的报道数量呈井喷式增长.至2014年5月钙钛矿电池光电转化效率已接近20%,已超过有机及染料敏化太阳能电池的效率,且有望达到单晶硅太阳能的水平,成为光伏发电领域中的希望之星.在钙钛矿电池中,电子传输材料与吸收层的电子选择性接触对提高光电转化效率起到重要作用,尤其在正置结构器件中,电子传输层的介观结构直接影响钙钛矿的生长情况.同时,电子传输层的化学性质及其界面也会对电池的稳定性和寿命产生影响.本文总结了电子传输材料在该类电池中的研究现状和热点,并按材料的化学组分不同,将电子传输材料分为三类:金属氧化物、有机小分子和复合材料,详细地介绍了电子传输材料在钙钛矿太阳能电池中的作用和近来的最新进展.

Ever since the first organic-inorganic hybrid halogen perovskite solar cell was first used as a photo-voltaic material in 2009, reports on this type of solar cell have grown exponentially over the years. Up till May 2014, the photoenergy conversion efficiency of the perovskite solar cell have already achieved an efficiency approaching 20%. Surpassing the efficiency achieved by organic and dye synthesized solar cell, the perovskite solar cell is in good hope of reaching the efficiency compatible with that of mono-crystalline silicon solar cell, thus it is going to be the star in photo-voltaic industry. In a perovskite solar cell, the film-formation and electron-mobility in the electron transfer layer can dramatically affect its efficiency and life-span. Especially in the up-right structured device, the mesoscopic structures of the electrontransfer layer will directly influence the growth of the perovskite layer. The present researches of electron transport materials mainly focus on three aspects：（1） How to improve the instability in mesoporous Ti O2-mesosuperstructured solar cells, that arises from light-induced desorption of surface-adsorbed oxygen.（2） How to obtain Ti O2 or other electron transport materials at low temperature（sub 150°C） in order to be applicatable in flexible devices.（3） How to substitute the mesoporous Ti O2 or compact Ti O2 transport layer by organic or composite materials. This article devides the materials that are used to make the electron-transfer layer into three distinct groups according to their chemical composition： i.e. metal oxides, organic small molecules, and composite materials, and introduces about the role they play and the recent development of them in constructing the perovskite solar cell.