Transparent pn junction of Mg:NiO/ZnO/SnO2 via potential regulation and carrier injection of ZnO transition layer

Transparent pn junction of Mg:NiO/ZnO/SnO2 is prepared via an approach of continuous co-sputtering annealing method. The Mg:NiO/ZnO/SnO2 pn junction exhibits high transmittance of-70-85 % in visible light, obvious photovoltaic enhancement of-1.6 x 102 folds than that of unmodified Mg:NiO/SnO2, stable output during 9 weeks' cycle. It's mainly attributed to the ultrathin ZnO transition layer, obtaining appropriate Fermi level and higher intrinsic carrier concentration can optimize carrier equilibrium, meanwhile sustaining high transparency and providing interface optimization. Furthermore, the extra hole carrier caused by Ni vacancy and Ni2+/Ni3+ mixed state can take full advantage of the defects to optimize the kinetic equilibrium. Additionally, the intrinsic high physical-chemical properties of inorganic NiO, ZnO and SnO2 can increase the intrinsic stability.