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 &mgr;m andR0Aas high as 200 &OHgr; cm2at 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 thep‐HgCdTe ton‐type at growth temperatures as high as 500 °C.