Executive Summary : | Gallium oxide (Ga₂O₃) has emerged as an important material for high power electronics and optoelectronic applications with its band gap in the deep ultraviolet (DUV) region. Thus solar-blind DUV photodetectors (e.g., flame detectors) have been reported as one of its many applications in the field of electronics. Ga₂O₃ exhibits several remarkable properties. Its breakdown electric field may reach a maximum value of 9 MV cm-¹. Materials with large electron concentrations in the range of 10¹⁵–10¹⁹ cm-³ by Si or Sn doping, and wider range of adjustable resistivity covering 10³–10¹² ??-cm are also reported. Ga₂O₃ is very stable against oxidation in normal as well as high temperature environment, thus, it may find its application is deep space mission and harsh atmospheric conditions. Due to its excellent material properties and low cost together with the availability of large native substrates, Ga₂O₃ has the potential to provide a significant usefulness in a wide range of applications. However, lack of p-type conductivity restricts β-Ga₂O₃ from its use in bipolar devices, such as BJT, PIN diodes, etc. β-Ga₂O₃ thin films can be successfully grown on various substrates by different film growth techniques for different device applications. However, the quality of the films in terms of the crystalline quality depends greatly on the type of the growth. For film deposition, particularly, in our country, techniques such as PLD, mist CVD and sputtering are used, however, the crystalline quality of the films is poor and full of unintentional defects. More precise techniques, such as atomic layer deposition and molecular beam epitaxy can grow device quality β-Ga₂O₃ thin films, however, these methods cannot be employed for large scale industrial production. On the other hand, MOCVD (metal organic chemical vapor deposition) is an attractive growth technique because it offers good compositional control, conformal or step coverage and can easily be scaled up for large area production. MOCVD grown films are reported to show better crystallinity compared to other techniques, especially for electronic applications. Moreover, MOCVD is also suitable to grow different types of β-Ga₂O₃ nanostructures such as nanowires and quantum dots. On the other hand, PI has the required expertise in the MOCVD growth of III-V semiconductors. Suitable dopants for the p-type conduction with high hole density is still not achieved due to large density of deep donor defect states, which act as hole trap center. From our theoretical study, it is observed that zinc (Zn), phosphorous (P), arsenic and co-doping method of Zn-P and Zn-As can play an important role in fabricating p-type β-Ga₂O₃, because donor acceptor repulsion pushes the acceptor states downward and donor states upward. Thus in this project, it is proposed to grow p-type Ga₂O₃ to enable fabrication of PIN based solar blind photodetectors with the device structure n-Ga₂O₃/i-Ga₂O₃/p-Ga₂O₃. |