DLTS analysis of WSe/sub 2/ solar cells

Abstract

In/p-WSe/sub 2/ and n-ZnO/p-WSe/sub 2/ junctions are investigated by DLTS. In both kinds of diode a dominant trap concentration is observed at 460 meV for unintentionally doped WSe/sub 2/ crystals. Lower trap concentrations are found to be at 200 meV and 300 meV. The devices exhibit temperature-dependent capacities and capture rates. SIMS and laser mass spectrometry analyses reveal that these crystals are mainly contaminated by Mo, Cr, V, Fe, and Cu. DLTS measurements on WSe/sub 2/ crystals that were doped by these elements during the single-crystal growth of ion etching, indicate that the trap at 460 meV may not be due to the detected impurities Mo and Cu.<>