Few-Layer MoS2/a-Si:H Heterojunction Pin-Photodiodes for Extended Infrared Detection
journal contributionposted on 13.05.2019, 00:00 by Andreas Bablich, Daniel S. Schneider, Paul Kienitz, Satender Kataria, Stefan Wagner, Chanyoung Yim, Niall McEvoy, Olof Engstrom, Julian Müller, Yilmaz Sakalli, Benjamin Butz, Georg S. Duesberg, Peter Haring Bolívar, Max C. Lemme
Few-layer molybdenum disulfide (FL-MoS2) films have been integrated into amorphous silicon (a-Si:H) pin-photodetectors. To achieve this, vertical a-Si:H photodiodes were grown by plasma-enhanced chemical vapor deposition (PE-CVD) on top of large-scale synthesized and transferred homogeneous FL-MoS2. This novel detector array exhibits long-term stability (more than six month) and outperforms conventional silicon-based pin-photodetectors in the infrared range (IR, λ = 2120 nm) in terms of sensitivities by up to ∼50 mAW–1. Photodetectivities of up to ∼2 × 1010 Jones and external quantum efficiencies of ∼3% are achieved. The detectors further feature the additional functionality of bias-dependent responsivity switching between the different spectral ranges. The realization of such scalable detector arrays is an essential step toward pixelated and wavelength-selective sensors operating in the IR spectral range.