Solution-Processed Phototransistors Combining Organic Absorber and Charge Transporting Oxide for Visible to Infrared Light Detection
Solution-Processed Phototransistors Combining Organic Absorber and Charge Transporting Oxide for Visible to Infrared Light Detection
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DOI：
10.1021/acsami.9b08622
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发表时间：
2019-10-09
影响因子：
9.5
通讯作者：
Ng, Tse Nga
中科院分区：
文献类型：
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作者：
Kim, Hyonwoong;Wu, Zhenghui;Ng, Tse Nga
本报告展示了高性能红外光电晶体管，使用宽带吸收有机体异质结（BHJ）层响应从可见光到短波红外，从500到1400 nm。该器件结构基于双层晶体管沟道，该沟道可并行电荷光生和传输，从而实现每个过程的独立优化。有机BHJ层通过掺入樟脑来改进，樟脑是一种高度可极化的添加剂，可增加载流子寿命。具有高电子迁移率的氧化铟锌传输层用于快速电荷传输。因此，光电晶体管实现了127 dB的动态范围，并在20 nW/cm（2）的低功率照明下达到5 x 10（12）Jones的比探测率，在低于1300 nm的光谱范围内优于商用锗光电二极管。相对于所施加的电压，入射光功率，和时间带宽，演示操作在50 Hz的视频帧速率的光电检测器的度量。特别地，分析了光电晶体管特性的频率和光依赖性，以了解在不同工作条件下光电导增益的变化。
This report demonstrates high-performance infrared phototransistors that use a broad-band absorbing organic bulk heterojunction (BHJ) layer responsive from the visible to the shortwave infrared, from 500 to 1400 nm. The device structure is based on a bilayer transistor channel that decouples charge photogeneration and transport, enabling independent optimization of each process. The organic BHJ layer is improved by incorporating camphor, a highly polarizable additive that increases carrier lifetime. An indium zinc oxide transport layer with high electron mobility is employed for rapid charge transport. As a result, the phototransistors achieve a dynamic range of 127 dB and reach a specific detectivity of 5 x 10(12) Jones under a low power illumination of 20 nW/cm(2), outperforming commercial germanium photodiodes in the spectral range below 1300 nm. The photodetector metrics are measured with respect to the applied voltage, incident light power, and temporal bandwidth, demonstrating operation at a video-frame rate of 50 Hz. In particular, the frequency and light dependence of the phototransistor characteristics are analyzed to understand the change in photoconductive gain under different working conditions.