Tunable Graphene-Silicon Heterojunctions for Ultrasensitive Photodetection
Tunable Graphene-Silicon Heterojunctions for Ultrasensitive Photodetection
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DOI：
10.1021/nl303682j
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发表时间：
2013-03-01
期刊：
影响因子：
10.8
通讯作者：
Kar, Swastik
中科院分区：
文献类型：
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作者：
An, Xiaohong;Liu, Fangze;Kar, Swastik
研究了石墨烯/硅异质结在光电流模和光电压模两种模式下的光检测特性。单层石墨烯/硅结是一种性能优良的弱信号探测器，光电压响应率超过10(7)V/W，噪声等效功率接近1PW/Hz(1/2)，有可能在0.5S积分时间内区分透过率为T=0.9995的材料。在光电流模式下，发现该响应在至少60年的入射功率(P)内保持线性，通过层增厚和掺杂获得了高达435 mA/W的可调响应度(对应于入射光子转换效率(IPCE)和GT；65%)。这些光电二极管具有毫秒级的响应和超过10(4)的通断比，非常适合用于可调谐和可扩展的宽带(400；lt；lambda；900 nm)光电探测器、光度计和毫秒响应开关、光谱和成像设备，而且在架构上与片上低功耗光电子兼容。
We present the photodetection properties of graphene/Si heterojunctions both in the photocurrent and photovoltage modes. Mono layer graphene/Si junctions were found to be excellent weak-signal detectors with photovoltage responsivity exceeding 10(7) V/W and with noise-equivalent-power reaching similar to 1 pW/Hz(1/2), potentially capable of distinguishing materials with transmittance, T = 0.9995 in a 0.5 s integration time. In the photocurrent mode, the response was found to remain linear over at least six decades of incident power (P), with tunable responsivity up to 435 mA/W (corresponding to incident photon conversion efficiency (IPCE) > 65%) obtained by layer thickening and doping. With millisecond-scale responses and ON/OFF ratios exceeding 10(4), these photodiodes are highly suitable for tunable and scalable broadband (400 < lambda < 900 nm) photodetectors, photometers, and millisecond-response switching, spectroscopic and imaging devices, and further, and are architecturally compatible with on-chip low-power optoelectronics.