Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University , Jiangsu, Suzhou 215123, China.
ACS Appl Mater Interfaces. 2015 Jan 28;7(3):2039-45. doi: 10.1021/am5079144. Epub 2015 Jan 15.
Organic/inorganic hybrid devices are promising candidates for high-performance, low-cost optoelectronic devices, by virtue of their unique properties. Polycrystalline/amorphous organic films are widely used in hybrid devices, because defects in the films hamper the improvement of device performance. Here, we report the construction of 2,4-bis[4-(N,N-dimethylamino)phenyl]squaraine (SQ) nanowire (NW)/crystalline Si (c-Si) p-n heterojunctions. Thanks to the high crystal quality of the SQ NWs, the heterojunctions exhibit excellent diode characteristics in darkness. It is significant that the heterojunctions have been found to be capable of detecting broadband light with wavelengths spanning from ultraviolet (UV) light, to visible (Vis) light, to near-infrared (NIR) light, because of the complementary spectrum absorption of SQ NWs with Si. The junction is demonstrated to play a core role in enhancing the device performance, in terms of ultrahigh sensitivity, excellent stability, and fast response. The photovoltaic characteristics of the heterojunctions are further investigated, revealing a power conversion efficiency (PCE) of up to 1.17%. This result also proves the potential of the device as self-powered photodetectors operating at zero external bias voltage. This work presents an important advance in constructing single-crystal organic nanostructure/inorganic heterojunctions and will enable future exploration of their applications in broadband photodetectors and solar cells.
有机/无机杂化器件因其独特的性质而成为高性能、低成本光电设备的有前途的候选者。多晶/非晶态有机薄膜广泛应用于杂化器件中，因为薄膜中的缺陷阻碍了器件性能的提高。在这里，我们报告了 2,4-双[4-(N,N-二甲基氨基)苯基]方酸菁（SQ）纳米线（NW）/晶体硅（c-Si）p-n 异质结的构建。由于 SQ NW 的高晶体质量，异质结在黑暗中表现出优异的二极管特性。值得注意的是，由于 SQ NW 与 Si 的互补光谱吸收，异质结已经被发现能够检测从紫外线（UV）光到可见光（Vis）光再到近红外（NIR）光的宽带光，这具有重要意义。该结在提高器件性能方面发挥了核心作用，具有超高灵敏度、优异的稳定性和快速响应。进一步研究了异质结的光伏特性，揭示出高达 1.17%的功率转换效率（PCE）。这一结果也证明了该器件作为自供电光电探测器在零外部偏置电压下工作的潜力。这项工作在构建单晶有机纳米结构/无机异质结方面取得了重要进展，将为未来探索其在宽带光电探测器和太阳能电池中的应用铺平道路。
