Plasmonic Pt nanoparticles triggered efficient charge separation in TiO2/GaN NRs hybrid heterojunction for the high performance self-powered UV photodetectors

• Published in: Applied surface science 2022-08, Vol.594, p.153474, Article 153474
• Main Authors: Pasupuleti, Kedhareswara Sairam, Chougule, Sourabh S., Jung, Namgee, Yu, Young-Jun, Oh, Jae-Eung, Kim, Moon-Deock
• Format: Article
• Language: English
• Subjects: GaN nanorods; Hybrid heterointerface junction; Plasmonic effect; Self-powered UV photodetector; TiO2 nanosheets
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2022.153474

[Display omitted] •A high performance self-powered UV photodetector was constructed based on Pt NP decorated TiO2/GaN NRs hybrid heterojunction.•The hybrid device showed excellent responsivity, detectivity, EQE and high UV to the visible rejection ratio.•LSPR induced hot electrons are significantly improve the charge carrier’s generation in the hybrid device.•Excellent charge separation and transportation at hybrid heterojunctions are responsible for augmented device performances.•The present study paves a pathway to improve the performances of UV photodetectors with other nanomaterials system. Solar radiation, especially the UV-A light rays (320–400 nm) exposure causes severe health hazard such as skin-related cancer and premature aging. Owing to the significance of UV-A photodetection, a high-performance UV-A photodetectors (PD) with high sensitivity, large detectivity and fast response time, have attracted great attention in various optoelectronic applications. Herein, we report a self-powered (SP) UV PD based on Pt nanoparticles (NP) decorated TiO2/GaN nanorods (NRs) hybrid heterojunction. The proposed Pt NP@TiO2/GaN NRs hybrid device demonstrates pronounced photoelectric performances including a large responsivity (44.6 A/W), superior detectivity (1.57 × 1014 Jones) and high electronic quantum efficiency (8.65 × 103 %) under the UV light intensity (λ = 382 nm, 1.32 mW/cm2) at zero bias, which are relatively much higher as compare to the pristine counterparts. In addition, the hybrid PD showed a short response/recovery times of 180 ms/200 ms, with a remarkable reproducibility and long-term stability towards the UV light. The impressive photoresponse properties of the hybrid SP PD are ascribed to the large photon absorption endorsed by the localized surface plasmonic resonance effect of Pt NP and the adequate built-in potential at the TiO2 and GaN NRs heterojunction interface, which further endows the effective separation and transport of photogenerated charge carriers. Furthermore, the plausible mechanism for the high-performances of hybrid UV PD is demonstrated in detailed using the energy band diagram. Our work reveals that the integral advantages of hybrid heterostructures, have a significant potential for the practical applications of advanced optoelectronics and high-performance SP UV-A PD.