Nat Mater. 2012 Feb 26;11(4):301-5. doi: 10.1038/nmat3256.
The composition of amorphous oxide semiconductors, which are well known for their optical transparency, can be tailored to enhance their absorption and induce photoconductivity for irradiation with green, and shorter wavelength light. In principle, amorphous oxide semiconductor-based thin-film photoconductors could hence be applied as photosensors. However, their photoconductivity persists for hours after illumination has been removed, which severely degrades the response time and the frame rate of oxide-based sensor arrays. We have solved the problem of persistent photoconductivity (PPC) by developing a gated amorphous oxide semiconductor photo thin-film transistor (photo-TFT) that can provide direct control over the position of the Fermi level in the active layer. Applying a short-duration (10 ns) voltage pulse to these devices induces electron accumulation and accelerates their recombination with ionized oxygen vacancy sites, which are thought to cause PPC. We have integrated these photo-TFTs in a transparent active-matrix photosensor array that can be operated at high frame rates and that has potential applications in contact-free interactive displays.
非晶氧化物半导体的组成，由于其光学透明度而广为人知，可以进行调整以增强其对绿光和更短波长光的吸收，并诱导光电导。原则上，基于非晶氧化物半导体的薄膜光电导体可以用作光电传感器。然而，它们的光电导在光照去除后持续数小时，这严重降低了基于氧化物的传感器阵列的响应时间和帧率。我们通过开发一种栅控非晶氧化物半导体光电薄膜晶体管（photo-TFT）来解决持久光电导（PPC）问题，该晶体管可以直接控制有源层中的费米能级位置。对这些器件施加短持续时间（10 ns）的电压脉冲会引起电子积累，并加速它们与被认为导致 PPC 的离子氧空位的复合。我们已经将这些 photo-TFT 集成到透明有源矩阵光电传感器阵列中，该阵列可以以高帧率运行，并且在非接触式交互式显示器中有潜在的应用。
