A photovoltaic device includes a substrate structure and at least one Se-containing layer, such as a CdSeTe layer. A process for manufacturing the photovoltaic device includes forming the CdSeTe layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process can also include controlling a thickness range of the Se-containing layer.

A photon avalanche diode, includes a quartz substrate, a doped HgCdTe contact layer on the substrate, an absorbing HgCdTe layer on the contact layer, a larger bandgap HgCdTe layer on the absorbing layer, a doped HgCdTe layer for a top contact layer on the larger bandgap HgCdTe layer, and a non-absorbing HgCdTe metasurface on the top contact layer.

A method of baking a detector, the method comprising: placing a mid-wave infrared detector in an environmental chamber, wherein the environmental chamber is opaque. The mid-wave infrared detector comprises an anode, a guard terminal, and a cathode. The method further comprising connecting the anode to the cathode in a short circuit configuration, heating the environmental chamber to a bake temperature selected in the range of 60 to 70 degrees Celsius, and maintaining the detector in the environmental chamber for a period selected in the range of 72 hours to 240 hours.

A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer. A photovoltaic device may include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSeTe layer over a substrate. The process includes forming a p-type cadmium selenide telluride absorber layer.

A photovoltaic cell can include an interfacial layer in contact with a semiconductor layer.