Study Of Growth And Characteristics Of GaN/Cu₂O Films Under Low- Temperature

Cuprous oxide (Cu2O) is an intrinsic p-type conductive semiconductor material with a direct band gap of 2.0 eV-2.6eV. It’s non-toxic and it has rich raw materials, besides, its production cost is relatively low. All these features make its volume production come true with a variety of devices. Also, due to its stabler photoelectric performance, stronger solar absorption coefficient and theoretically higher photoelectric conversion efficiency, Cu2O has an important scientific significance and has been widely applied in those fields such as electronic devices, magnetic materials, gas sensors, biosensors, optical devices and electrode materials for lithium-ion batteries.Gallium nitride (GaN) is a member of nitride semiconductor materials that have direct wide-band gaps. It has such advantages as cheap price and high efficient performance. In addition to its application on high frequency and large power devices, it is also irreplaceable in the application of short wavelength optoelectronic devices as its band gap is wide enough to cover the entire visible spectrum. With the continuous improvement of GaN preparation technology, the blue light emitting diode (LED) whose component material is GaN is rapidly becoming industrialized.The n-GaN/p-Cu2O semiconductor heterojunction that this paper studied grew on cheap glasses, and there is no limitation on the size of the substrate. What’s more, these two kinds of material are cheap, therefore much cheaper photoelectric devices can be prepared.In this paper, we got Cu2O films by using radio frequency magnetron devices sputtering high purity copper (5N) on the glass substrate, with the presence of oxygen and argon gases. And the author also studied the influence of different oxygen flux and temperatures on the structural, optical and electrical properties of the grown films through a series of thin film characterization methods.Then by using this electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD) method, GaN films were deposed under low-temperature on the glass substrates where P-Cu2O films were grown. The influences of different TMGa flux on the current-illumination characteristics of GaN/Cu2O/glass were systematically studied through a variety of characterization methods. The results indicate that GaN films have good crystal quality with a TMGa flow rate of 1.0 sccm. Owing to the growth of GaN buffer layer at low temperature, the electron tunneling on the interface of GaN/Cu2O heterojunction occurs which shows the ohmic contact characteristics.