Structural Properties and Absorption Band Edge Tunability in ZnMnO by Metal-organic Chemical Vapor Deposition and Atomic Layer Deposition

Zinc manganese oxide (ZnMnO) grown by metal-organic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD) exhibit absorption band edge tunability with Mn incorporation. ZnMnO with good crystal quality oriented in the (002) direction was grown using MOCVD. ALD-grown ZnMnO was amorphous but exhibited high crystallinity after annealing at 800 degrees C for 1 hour. ZnMnO using both growth techniques showed an overall reduction in band edge with Mn incorporation, but the trend was scattered. The band edge reduction is influenced by energy states and oxidation states of Mn incorporated in ZnMnO rather than the cumulative Mn incorporation. Incorporation of Mn with oxidation states favorable to achieve bandgap tunability could be controlled with growth techniques and growth conditions. Control over energy states introduced by Mn in ZnMnO could enable application of ZnMnO for various areas of interest including spintronics, photovoltaics, photodiodes, and sensing.