Ultrahigh-sensitivity CdS photoconductors with instant response and ultralow power consumption for detection in low-light environments
Ultrahigh-sensitivity CdS photoconductors with instant response and ultralow power consumption for detection in low-light environments
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DOI：
10.1039/c3tc30520a
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发表时间：
2013-06
影响因子：
6.4
通讯作者：
Keng-Te Lin;S. Tseng;Hsuen‐Li Chen;Y. Lai;Szu-Huang Chen;Y. Tseng;Ting-Wei Chu;Ming-Yu Lin;Yen-Pei Lu
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文献类型：
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作者：
Keng-Te Lin;S. Tseng;Hsuen‐Li Chen;Y. Lai;Szu-Huang Chen;Y. Tseng;Ting-Wei Chu;Ming-Yu Lin;Yen-Pei Lu
在这项研究中，我们描述了一种低成本的硫化镉（cd）光导体，其表现为对低强度光的高灵敏度和快速响应探测器。通过TEM图像观察和微拉曼光谱分析，经KrF准分子激光多次照射后，CdS薄膜的结晶程度提高，位错缺陷得到有效去除。这种激光处理CdS光导体可以在空气中进行，并在几秒钟内完成。在1 mV的极低偏置电压下，激光处理的CdS器件提供了创纪录的7200 a W−1的高响应率和1015 Jones的探测率。此外，在1 V的正偏置电压下，它显示出极高的响应度，为7 × 106 a W−1，探测率为6 × 1016 Jones。激光退火CdS器件在10−2 fW μm−2下从黑暗到照明的响应时间仅为40 ms，远远快于专业数码相机用于这种弱光图像检测所需的快门速度或曝光时间。因此，KrF激光退火是一种简单快速的工艺，可以显著提高商用光导体cd的弱光探测性能。我们在此提出的策略似乎具有超低功耗的超低光图像检测的巨大潜力。
In this study we describe a low-cost cadmium sulfide (CdS) photoconductor that behaves as a highly sensitive and rapidly responding detector toward low-intensity light. Through the observation of TEM images and analysis of micro-Raman spectra, the degree of crystallization of CdS films increased and their dislocation defects were removed effectively after treatment with several shots from a KrF excimer laser. Such laser treatment of CdS photoconductors could be conducted in air and completed within a few seconds. At a very low bias voltage of 1 mV, the laser-treated CdS device provided a record high responsivity of 7200 A W−1 and a detectivity of 1015 Jones. In addition, at a normal bias voltage of 1 V, it displayed an extremely high responsivity of 7 × 106 A W−1 and a detectivity of 6 × 1016 Jones. The measured response time of the laser-annealed CdS device from the dark to illumination at 10−2 fW μm−2 was only 40 ms—much faster than the shutter speed or exposure time required for a professional digital camera for such low-light image detection. Accordingly, KrF laser annealing is a simple and rapid process that can significantly enhance the low-light detection properties of CdS, a commercial photoconductor. Our strategy proposed herein appears to hold great potential for ultralow-light image detection with ultralow power consumption.