Kim Myeong In, Kang Jinhyeon, Park Jaehee, Jeong WonJo, Kim Junho, Yim Sanggyu, Jung In Hwan
Department of Organic and Nano Engineering, Human-Tech Convergence Program, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
Department of Energy Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
Molecules. 2022 Nov 7;27(21):7660. doi: 10.3390/molecules27217660.
Colloidal quantum dots (CQDs) have a unique advantage in realizing near-infrared (NIR) photodetection since their optical properties are readily tuned by the particle size, but CQD-based photodetectors (QPDs) presently show a high dark current density () and insufficient dynamic characteristics. To overcome these two problems, we synthesized and introduced two types of conjugated polymers (CPs) by replacing the -type CQD layer in the QPDs. The low dielectric constant and insulating properties of CPs under dark conditions effectively suppressed the in the QPDs. In addition, the energy-level alignment and high-hole mobility of the CPs facilitated hole transport. Therefore, both the responsivity and specific detectivity were highly enhanced in the CP-based QPDs. Notably, the dynamic characteristics of the QPDs, such as the -3 dB cut-off frequency and rising/falling response times, were significantly improved in the CP-based QPDs owing to the sizable molecular ordering and fast hole transport of the CP in the film state as well as the low trap density, well-aligned energy levels, and good interfacial contact in the CP-based devices.
胶体量子点（CQDs）在实现近红外（NIR）光探测方面具有独特优势，因为其光学性质可通过粒径轻松调节，但基于CQD的光电探测器（QPDs）目前显示出高暗电流密度（）和不足的动态特性。为克服这两个问题，我们通过替换QPDs中的型CQD层合成并引入了两种共轭聚合物（CPs）。CPs在暗条件下的低介电常数和绝缘特性有效抑制了QPDs中的。此外，CPs的能级排列和高空穴迁移率促进了空穴传输。因此，基于CP的QPDs中的响应度和比探测率均得到高度提高。值得注意的是，基于CP的QPDs中QPDs的动态特性，如-3 dB截止频率和上升/下降响应时间，由于CP在薄膜状态下可观的分子有序性和快速的空穴传输以及基于CP的器件中的低陷阱密度、良好排列的能级和良好的界面接触而得到显著改善。
