Research Of MgZnO Ultraviolet Photodetectors

Due to wide tunable band gap?3.3 eV ⁷.8 eV?,availability of homogeneous single crystal substrate,low preparation temperature,abundant resources,strong radiation-resistence,and environment harmless,MgZnO semiconductor materials have been considered as promising candidate in ultraviolet?UV?photodetector.High quality MgZnO films were fabricated by radio-frequency?RF?magnetron sputtering technology,and the metal-semiconductor-metal?MSM?structured MgZnO photodetectors were defined by conventional lithography and wet etching in this thesis.The main researches are as follows:?1?High quality MgZnO films were fabricated by RF magnetron sputtering on SiO₂ substrates with different Mg contents,and the continuous tunable band-gap of MgZnO were achieved from visible-blind to solar-blind,in which the cubic Mg_0.60Zn_0.40O film with was prepared by the subsection method.The crystalline and optical performances of the MgZnO films have been researched.Besides,the relationship between the content of Mg in the MgZnO film and the optical performance of the corresponding film has been detailed.?2?The MSM structured MgZnO photodetectors with different Mg contents were defined by conventional lithography and wet etching.The effect of the signal resistors on the ZnO photodetectors has been detailed has been detailed.Furthermore,a study of the barrier height was detailed for the responsivity differences between Mg_0.20Zn_0.80 O and Mg_0.42Zn_0.58O photodetectors.We succeeded in fabricating Mg_0.60Zn_0.40O solar-blind photodetectors by the subsection method,and its performance was analyzed systematically.?3?The depletion width can be changed by adjusting the distance between the interdigitated electrodes,and then the responsivities and the dark currents of the MSM structured MgZnO UV photodetectors can be regulated simultaneously,and gave an in depth analysis in the physical mechanism of the metal-semiconductor contact.