Advancing infrared detection: graphene’s potential and stability in varied environments

Abstract

Graphene-based infrared detectors exhibit remarkable thermoelectric and photoresponse properties, yet their stability under varying environmental conditions remains a critical challenge. This study investigates the temperature-dependent performance of a graphene/hBN/(gold-hBN-gold) heterostructure infrared detector, focusing on the Seebeck coefficient, voltage response, and thermal stability. By analyzing the system under applied voltages of 0.3 to 0.6 V and temperatures from 300 to 500 K, we noted an enhanced Seebeck coefficient, achieving values up to \(-140\,\upmu\,{\rm V/ K}\). The thermoelectric figure of merit (ZT) improves with temperature, though its magnitude is inversely proportional to the initial operating temperature, highlighting the role of hBN in suppressing phonon-mediated thermal losses. Furthermore, the Brody parameter \((\beta = 0.58-0.7)\) confirms spectral selectivity in the \(36-54\;\) THz range. Current-density analysis reveals asymmetric transport behavior, with quantum tunneling dominating at positive biases \((> 2\,)\) V and stable p-n junction dynamics at negative biases. These findings demonstrate that optimized doping, hBN integration, and voltage control can mitigate thermal stress, enhancing graphene detectors’ scalability for infrared applications.