Comparative studies of metamorphic and strained InGaAs p-type semiconductor - intrinsic absorption layer - n-type semiconductor photodetector for low-temperature CH4 detection

• Published in: Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2024-12, Vol.42 (6)
• Main Authors: Du, Xueting, Niu, Kai, Mi, Wei, Wang, Di, Zhu, Yan, He, Lin’an, Zhou, Liwei, Wang, Juan, Zhang, Xingcheng, Zhao, Jinshi
• Format: Article
• Language: English
• ISSN: 2166-2746; 2166-2754
• DOI: 10.1116/6.0004069

This paper proposes two wavelength-extended InGaAs p-type semiconductor - intrinsic absorption layer - n-type semiconductor structures to achieve methane detection at low temperatures. The responsivity of the strained and metamorphic structures is 0.98 and 1.09 A/W at 20 °C. The strained structure detector can achieve a response level of 0.7 A/W in low-temperature environments above −10 °C. The metamorphic structure shows a responsivity not less than 0.8 A/W within the temperature span of −40 to 85 °C. The dark current of both devices is at the nA level at −10 V. The saturation optical power of the strained structure and the metamorphic structure is 13 and 17 mW at −0.5 V, respectively. The cut-off wavelength is 1690 and 1730 nm for the strained structure and the metamorphic structure. These two structures tested by x-ray diffraction have high crystalline quality. The strained structure has a root mean square roughness of 0.13 nm, while the metamorphic structure's roughness is 0.39 nm. These results suggest that both strained and metamorphic structures have promising applications in low-temperature probes.