ABSTRACT

Semiconductors as a class of material have found diverse applications that seem to be growing at an exponential rate. Single crystal zinc oxide (ZnO) is one such wide band gap semiconductor with great potential for a variety of commercial applications including substrates, UV photodetectors, acoustic wave devices, light emitting diodes, laser diodes, high frequency electronic devices, and ultrafast nuclear particle detectors. ZnO is an excellent candidate for extreme operating conditions required for some space and military applications as the material is highly resistant to radiation damage compared even to GaN. Melt-grown ZnO has the capability of producing high structural quality single crystal material. Very-high-quality ZnO bulk crystals have been grown using pressurized melt growth process. This is evidenced by the extremely high optical, structural, and electrical quality of the material. High-purity semi-insulating GaAs used for microwave devices is grown from an As-rich melt in a pressurized inert gas atmosphere with a liquid encapsulant in a variation of the Czochralski method.