Department of Applied Physics, The Hong Kong Polytechnic University , Hong Kong, China.
ACS Appl Mater Interfaces. 2017 Jan 18;9(2):1569-1576. doi: 10.1021/acsami.6b11631. Epub 2017 Jan 4.
Organometal halide perovskite materials have attracted much attention recently for their excellent optoelectronic properties. Here, we report an ultrasensitive phototransistor based on the multiheterojunction of CHNHPbICl perovskite/poly(3-hexylthiophene)/graphene for the first time. Since the photoexcited electrons and holes are effectively separated by the poly(3-hexylthiophene) layer, high-density electrons are trapped in the perovskite layer, leading to a strong photogating effect on the underlying graphene channel. The phototransistor demonstrates an unprecedented ultrahigh responsivity of ∼4.3 × 10 A/W and a gain approaching 10 electrons per photon, respectively. More importantly, the device is sensitive in a broadband wavelength region from ultraviolet to near-infrared, which has not yet been achieved with other perovskite photodetectors. It is expected that the novel perovskite phototransistor will find promising applications as photodetection and imaging devices in the future.
金属有机卤化物钙钛矿材料因其优异的光电性能而受到广泛关注。在这里，我们首次报道了基于 CHNHPbICl 钙钛矿/聚（3-己基噻吩）/石墨烯的多异质结的超灵敏光电晶体管。由于聚（3-己基噻吩）层有效地分离了光激发的电子和空穴，高密度的电子被捕获在钙钛矿层中，从而对下面的石墨烯沟道产生强烈的光栅效应。该光电晶体管的响应率高达 4.3×10^A/W，增益接近每个光子 10 个电子，这是前所未有的。更重要的是，该器件在从紫外到近红外的宽带波长范围内具有灵敏度，这是其他钙钛矿型光电探测器尚未实现的。预计这种新型钙钛矿光电晶体管将在未来的光电探测和成像器件中得到广泛应用。
