Trapping lifetime and carrier mobility measurements in CuInSe(2 ) using surface-acoustic-wave technique

A novel technique based on the measurement of the frequency spectrum of the acoustoelectric current is used to determine the trapping time associated with dominant traps in p-type CuInSe(2). At room temperature, two trap levels with trapping time constant of 2x10(-4) and 6.7x10(-5) s are detected. Under white incandescent light, two more traps with trapping time constants of 1.4x10(-3) and 6x10(-4) s are detected. The minority (electron) and majority (hole) carrier mobilities in this material are also measured using the acoustoelectric technique, and they are 6+/-3 and 3.1+/-0.15 cm(2)/V-s, respectively. The hole carrier concentration was estimated to be around 5x10(15) cm(-3), and the surface of the sample was depleted.