Stable, Fast UV-Vis-NIR Photodetector with Excellent Responsivity, Detectivity, and Sensitivity Based on α-In2Te3 Films with a Direct Bandgap.
Stable, Fast UV-Vis-NIR Photodetector with Excellent Responsivity, Detectivity, and Sensitivity Based on α-In2Te3 Films with a Direct Bandgap.
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DOI：
10.1021/acsami.6b06222
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发表时间：
2016-08
影响因子：
9.5
通讯作者：
Jiandong Yao;Z. Deng;Zhaoqiang Zheng;Guowei Yang
中科院分区：
文献类型：
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作者：
Jiandong Yao;Z. Deng;Zhaoqiang Zheng;Guowei Yang
光电转换在广泛的应用中具有重要意义。然而，到目前为止，集成了高响应率、良好的探测率、大的光暗电流比、快速的响应速度、宽的光谱范围和良好的稳定性的光电探测器还很少。在本论文中，我们采用脉冲激光沉积的方法制备了大规模、高质量的多晶倍半硫化铟(α-In2Te3)薄膜。结果表明，由所制备的α-In2Te3薄膜制成的光电探测器在370~1064 nm范围内具有稳定的光开关行为，响应时间优于约15ms。在5V的源漏电压下，该器件获得了44A/W的高响应度，6×10(12)cm H(1/2)W(-1)的出色探测率和2.5×10(5)cm(2)/W的优异灵敏度。所有这些性能指标都是已报道的α-In2Te3光电探测器中最好的。事实上，它们可以与最先进的商用硅和锗光电探测器相媲美。首次从理论上证明了α-In_2Te_3具有直接带隙结构，合理地解释了其优异的光探测性能。重要的是，该器件在多次光开关操作和环境中表现出良好的稳定性，并且没有明显的电压扫描滞后。这些优良的品质因数，加上宽广的光谱范围和良好的稳定性，使α-In2Te3成为下一代光探测的一种有前途的候选材料。
Photoelectric conversion is of great importance to extensive applications. However, thus far, photodetectors integrated with high responsivity, excellent detectivity, large phototo-dark current ratio, fast response speed, broad spectral range, and good stability are rarely achieved. Herein, we deposited large-scale and high-quality polycrystalline indium sesquitelluride (α-In2Te3) films via pulsed-laser deposition. Then, we demonstrated that the photodetectors made of the prepared α-In2Te3 films possess stable photoswitching behavior from 370 to 1064 nm and short response time better than ca. 15 ms. At a source-drain voltage of 5 V, the device achieves a high responsivity of 44 A/W, along with an outstanding detectivity of 6 × 10(12) cm H(1/2) W(-1) and an excellent sensitivity of 2.5 × 10(5) cm(2)/W. All of these figures-of-merit are the best among those of the reported α-In2Te3 photodetectors. In fact, they are comparable to the state-of-the-art commercial Si and Ge photodetectors. For the first time, we established the theoretical evidence that α-In2Te3 possesses a direct bandgap structure, which reasonably accounts for the superior photodetection performances above. Importantly, the device exhibits a good stability against the multiple photoswitching operation and ambient environment, along with no obvious voltage-scan hysteresis. These excellent figures-of-merit, together with the broad spectral range and good stability, underscore α-In2Te3 as a promising candidate material for next-generation photodetection.