HgCdTe photovoltaic detectors on Si substrates

Abstract

HgCdTe infrared photovoltaic detectors were fabricated on silicon substrates for the first time by using intermediate CdTe and GaAs epitaxial layers. No cracking or degradation was observed after thermal cycling these devices (cutoff wavelength of 5.5 μm and R₀A as high as 200 Ω cm² at 80 K). Secondary ion mass spectrometry and Auger data substantiate that a CdTe buffer layer can prevent Ga diffusion from the intermediate GaAs epitaxial layer from inadvertently converting the p‐HgCdTe to n‐type at growth temperatures as high as 500 °C.