Improving of Sensitivity of PbS Quantum Dot Based SWIR Photodetector Using P3HT

Abstract

In this study, we improved the photosensitivity of the lead sulfide quantum dot (PbS QD)-based shortwave infrared (SWIR: 1.0–2.5 μm) photodetector by blending poly(3-hexylthiophene-2,5-diyl) (P3HT) with PbS QD. The PbS QD used for SWIR photoactive layer showed an absorption peak at 1410 nm. In addition, by using zinc oxide nanoparticles (ZnO NPs) as an interlayer, we obtained the stable current characteristics of our device. To confirm the effectiveness of P3HT on the PbS QD-based SWIR photodetector, we compared the electrical characteristics of a PbS QD-based device with a hybrid P3HT:PbS QD-based device. In the reverse bias region, the current on/off ratio of the PbS QD-based device was 1.3, whereas the on/off ratio of the hybrid P3HT:PbS QD-based device was 2.9; 2.2 times higher than the PbS QD-based device. At −1 V, the on/off ratio of the PbS QD-based device was 1.3 and the on/off ratio of the hybrid P3HT:PbS QD-based device was 3.4; 2.6 times higher than the PbS QD-based device. The fabricated P3HT:PbS QD-based device had the highest on/off ratio when −1 V voltage was applied.

Shortwave Infrared Photodetection with oCVD Polythiophene

“…Organic materials are attractive because they can be directly deposited onto readout integrated circuits (ROICs), eliminating the need for hybridization. Concepts such as polymerfunctionalized lead salts, [10] quinonebased organometallic semiconductors, [11] graphene, [12] phototransistors, [13] and photodiodes [14] have been explored, but their performance remains predominantly limited to the near-infrared region (NIR, 𝜆 = 0.75-1 μm). Polymer-based IR detectors have difficulty extending into the short-wave infrared region (SWIR, 𝜆 = 1-3 μm), with cutoff wavelengths around 1.5 μm being common.…”

Study on chemical bath-deposited PbS thin films with subsequent rapid thermal treatment: treatment temperature-dependent microstructure and near-infrared absorption

“…0.41 eV direct band gap energy [1] and a 18 nm exciton Bohr radii at 300 K [2]. These properties make PbS have potential applications including infrared photodetectors [3,4], gas sensors [5] and quantum-dot solar cells [6,7]. In the past years, PbS films have been performed intensive study for their excellent infrared properties.…”

“…The main aim of these studies is to improve the optoelectronic properties and widen the application fields of PbS. Due to these studies, PbSbased photodetectors [3,4] and quantum dot solar cells [6,7] have been greatly improved in performance. In the future, nano-sized PbS-based devices including photodetectors and photovoltaic devices will still become the hotspot of research.…”