Design and Growth Optimization by Dual Ion Beam Sputtered ZnO-Based High-Efficiency Multiple Quantum Well Green Light Emitting Diode

摘要

This manuscript deals with a theoretical design of Cd_(0.4)Zn_(0.6)O/ZnO multiple quantum well light emitting diode using commercial simulation software and experimentally optimized growth conditions of n-type ZnO on Si (001) substrate by dual ion beam sputtering deposition system. Theoretical study reveals an internal quantum efficiency ～93.5% is achieved at room temperature from the device, emitting at 510 nm with a turn-on voltage of 3 V. The effect of substrate temperature on ZnO thin film has been investigated. Growth parameters optimization is performed using structural, electrical, optical and morphological characterizations. X-ray diffraction measurement show that the ZnO films grown at substrate temperatures of 200℃, 400℃ and 600℃ have a (002) preferred orientation. Four probe Hall measurements demonstrate achievements of a maximum carrier mobility of 26.53 cm~2/V · s with a low electrical resistivity of 0.062 Ω · cm and a carrier concentration of 3.8 × 10~(18) cm~(-3) at room temperature for the film grown at 500℃. Photoluminescence studies conducted at room temperature describe a strong band-edge emission at 380 nm from ZnO samples. Prominent photoluminescence shoulder peaks are observed at ～485 nm and 618 nm from ZnO film grown at 400℃.