Bansal Shonak, Sharma Kuldeep, Jain Prince, Sardana Neha, Kumar Sanjeev, Gupta Neena, Singh Arun K
Department of Electronics and Communication Engineering, Punjab Engineering College (Deemed to be University) Sector-12 Chandigarh-160012 India
Department of Metallurgical and Materials Engineering, Indian Institute of Technology Ropar India.
RSC Adv. 2018 Nov 27;8(69):39579-39592. doi: 10.1039/c8ra07683a. eCollection 2018 Nov 23.
We present a high-performance bilayer graphene (BLG) and mercury cadmium telluride (Hg Cd Te) heterojunction based very long wavelength infrared (VLWIR) conductive photodetector. The unique absorption properties of graphene enable a long carrier lifetime of charge carriers contributing to the carrier-multiplication due to impact ionization and, hence, large photocurrent and high quantum efficiency. The proposed p-BLG/n-HgCdTe photodetector is characterized and analyzed in terms of different electrical and optical characteristic parameters using computer simulations. The obtained results are further validated by developing an analytical model based on drift-diffusion, tunneling and Chu's methods. The photodetector has demonstrated a superior performance including improved dark current density (∼1.75 × 10 µA cm), photocurrent density (∼8.33 µA cm), internal quantum efficiency (QE ∼ 99.49%), external quantum efficiency (QE ∼ 89%), internal photocurrent responsivity (∼13.26 A W), external photocurrent responsivity (∼9.1 A W), noise equivalent power (∼8.3 × 10 W), total noise current (∼1.06 fA), signal to noise ratio (∼156.18 dB), 3 dB cut-off frequency (∼36.16 GHz), and response time of 9.4 ps at 77 K. Furthermore, the effects of different external biasing, light power intensity, and temperature are evaluated, suggesting a high QE of 3337.70% with a bias of -0.5 V near room temperature.
我们展示了一种基于高性能双层石墨烯（BLG）和碲镉汞（Hg Cd Te）异质结的甚长波长红外（VLWIR）导电光电探测器。石墨烯独特的吸收特性使电荷载流子具有较长的载流子寿命，这有助于因碰撞电离而产生载流子倍增，从而产生大的光电流和高量子效率。所提出的p型双层石墨烯/n型碲镉汞光电探测器通过计算机模拟，根据不同的电学和光学特性参数进行了表征和分析。通过基于漂移扩散、隧穿和朱方法开发分析模型，进一步验证了所得结果。该光电探测器表现出优异的性能，包括改善的暗电流密度（约1.75×10 μA/cm²）、光电流密度（约8.33 μA/cm²）、内量子效率（QE约99.49%）、外量子效率（QE约89%）、内光电流响应度（约13.26 A/W）、外光电流响应度（约9.1 A/W）、噪声等效功率（约8.3×10⁻¹² W）、总噪声电流（约1.06 fA）、信噪比（约156.18 dB）、3 dB截止频率（约36.16 GHz）以及在77 K时9.4 ps的响应时间。此外，还评估了不同外部偏置、光功率强度和温度的影响，结果表明在室温附近施加-0.5 V偏置时，量子效率高达3337.70%。
