THE MORPHOLOGY AND I-V CHARACTERISTICS OF O Mg Zn X X 1 THIN FILMS DEPOSITED BY SPRAY PYROLYSIS TECHNIQUE Salam A. Yousif a , Nadir F. Habubi *a , Abdulla A. Rasheed b Department of Physics, a (College of Education), b (College of Science), Al-Mustansiriyah University, Baghdad, Iraq nadirfadhil@yahoo.com Received 29-11-2012, online 6-11-2012 ABSTRACT Mg doped ZnO thin films were deposited on a glass substrate by spray pyrolysis technique at a substrate temperature equal to under ambient atmosphere. The energy-dispersive X-ray analysis (EDX) spectra of the O Mg Zn X X 1 thin films reveals that all the films contain the elements (Zn, Mg, O) as expected, indicating formation of the O Mg Zn X X 1 films with high purity. From the (SEM) images the grain size values of the O Mg Zn X X 1 thin films deposited by (SP) technique are found to be in the ranges of (59-83)nm, (35-59)nm, (47-71)nm, (47-59)nm, (35-47)nm corresponding to the Mg-concentrations (x = 0, 0.1, 0.2, 0.3, 0.4) respectively. The I-V characteristics of Si n O Mg Zn X X / 1 heterojunction for dark and illuminated conditions have been investigated. Keywords: thin film, O Mg Zn X X 1 , spray pyrolysis I. INTRODUCTION ZnO with bandgap has been investigated intensively due to its potential applications for laser diode (LD) and light emitting diode (LED) at ultraviolet or even blue light spectra. More interestingly, its large exciton binding energy makes the efficient excitonic emission at room temperature possible. For the development of ZnO film based optoelectronic devices, the realization of p-type conductivity ZnO thin film is considered to be a critical issue and has been investigated by various doping techniques[1,2]. Although ZnO is a hexagonal wurtzite-type structure and MgO is a cubic sodium chloride (NaCl) type structure , the similarity in ionic radii between and allows significant Zn/Mg replacement in either structure, while the lattice parameters are kept almost constant. Since the modulation of the bandgap with similar lattice constant is essential for construction of the heterojunction or superlattice to obtain high-performance (LD) and (LED) devices, hexagonal O Mg Zn X X 1 alloy film was found to be a very suitable barrier layer for ZnO/ O Mg Zn X X 1 superlattices [3] and multi-quantum wells [4]. Heterojunctions of TCO/Si have been reported to have good photovoltaic characteristics [5]. Since ZnO is a wide bandgap material , ZnO/Si heterojunction is expected to have a spectral responsivity that extend from NUV to NIR. Jeong [6] demonstrated a UV-enhanced ZnO/Si potodetector, he found that this detector exhibits strong responsivity of 0.5 and 0.3 A/W for UV 310 nm and red 650 nm photons, respectively. They also revealed that this detector shows a sign of reversal with a weak minimum near 380 nm. Doped ZnO films with other elements with different techniques have been reported by [7-9]. This work was focused on the morphological and I-V characteristic of Mg doped zinc oxide. II. EXPERIMENTAL A series of O Mg Zn X X 1 thin films with different Mg contents (x = 0, 0.1, 0.2, 0.3, 0.4) were deposited on a glass and silicon substrates by spray pyrolysis technique under ambient atmosphere. Journal of Electron Devices, Vol. 16, 2012, pp. 1347-1355 © JED [ISSN: 1682 -3427 ]