Abstract Perovskite photodetectors processing a photocurrent amplification have attracted much attention due to their high response to light illumination and have been exploited in a regular device geometry. Here, photocurrent amplification is demonstrated in an inverted perovskite photodetector, and the effect of the indium tin oxide (ITO)/perovskite interface on the photocurrent amplification factor are exploited. It is found that the photocurrent amplification is limited by the ITO/perovskite interface, which can be proved by the devices with bare ITO, Cu2O particles partially covered ITO, and poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) fully covered ITO as the anodes. A photocurrent amplification factor of about 27 is demonstrated in the perovskite photodetector with a bare ITO as the anode, which is one of the highest ones among the reported perovskite photodetectors. It also exhibits a maximum response of 4.1 A/W and a detectivity of 1011 Jones. Compared with the bare ITO device, the photocurrent amplification of the devices decreases gradually with the reduced contact area between ITO and perovskite and eventually disappears when the direct contact is totally removed. The photocurrent amplification is attributed to the long-lived accumulated holes as well as the positively charged CH3NH3+ and I vacancy at the ITO/perovskite interface, which dramatically lowers the injection barrier of electrons and leads to a multiple electron injection.

中文翻译：

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氧化铟锡/钙钛矿界面对钙钛矿光电探测器光电流放大的影响

摘要 处理光电流放大的钙钛矿光电探测器因其对光照的高响应而备受关注，并已在常规器件几何结构中得到利用。在这里，在倒置钙钛矿光电探测器中演示了光电流放大，并利用了氧化铟锡（ITO）/钙钛矿界面对光电流放大系数的影响。发现光电流放大受到ITO/钙钛矿界面的限制，这可以通过裸ITO、Cu2O颗粒部分覆盖ITO和聚(3,4-乙烯二氧噻吩):聚(苯乙烯磺酸盐)的器件来证明覆盖 ITO 作为阳极。在以裸 ITO 作为阳极的钙钛矿光电探测器中，光电流放大系数约为 27，这是已报道的钙钛矿光电探测器中最高的之一。它还具有 4.1 A/W 的最大响应和 1011 Jones 的探测能力。与裸ITO器件相比，器件的光电流放大率随着ITO与钙钛矿接触面积的减小而逐渐减小，并在完全去除直接接触时最终消失。光电流放大归因于长期累积的空穴以及带正电荷的 CH3NH3+ 和 ITO/钙钛矿界面处的 I 空位，这显着降低了电子的注入势垒并导致多电子注入。器件的光电流放大率随着 ITO 和钙钛矿之间接触面积的减小而逐渐减小，当直接接触完全去除时最终消失。光电流放大归因于长期累积的空穴以及带正电荷的 CH3NH3+ 和 ITO/钙钛矿界面处的 I 空位，这显着降低了电子的注入势垒并导致多电子注入。器件的光电流放大率随着 ITO 和钙钛矿之间接触面积的减小而逐渐减小，当直接接触完全去除时最终消失。光电流放大归因于长期累积的空穴以及带正电荷的 CH3NH3+ 和 ITO/钙钛矿界面处的 I 空位，这显着降低了电子的注入势垒并导致多电子注入。