Metal contacts to p-type crystalline copper indium diselenide

To find low resistance metal contacts on p-type crystalline copper indium diselenide (CuInSe₂), bilayers of metal contacts were deposited on p-type crystalline CuInSe₂. The first metals were Ni, Pt, Se, and Te and the second metals were Au, Ag, Al, and Cu. It was found that the resistance reduced significantly when the surface was etched in a solution containing H₂SO₄ (1%, w/w) and CrO₃ (1%, w/w). It was also confirmed that heat treatment often leads to increase contact resistance. The resistance was measured for over a period of 20 days to estimate the thermal stability of the metal contacts. It was observed that prolonged evacuation time before the metal deposition reduced the resistance.