Structural, Optical, and Electrical Characterization of ZnO and Al‐doped ZnO Thin Films Deposited by MOCVD

Abstract

A novel approach is used to deposit transparent Al-doped zinc oxide (AZO) films by metal-organic (MO) CVD using a Zn/Al safe, friendly to use, easily to handle, multimetal, liquid precursor source. Films are highly crystalline, (002) textured, and exhibit good transparency in the visible region (90%). The effects of Al doping on morphological, optical, and electrical performances are scrutinized. Al doping causes an energy gap (Eg) blue shift and a slight decrease in refractive index. Moreover, it favors sizeable changes in grain size and a surface integrity that are responsible for a reduced carrier mobility. Nevertheless, a minimum resistivity value of 5 Â 10 À2 V cm is obtained for thin ($150 nm) AZO films. Time resolved photoluminescence (TRPL) confirms the high crystal quality of deposited films. All features render present AZO films well suited for transparent conductive oxide (TCO) applications and suggest a great potential for the proposed fabrication method.

Using the acetylacetonates of zinc and aluminium for the Metalorganic Chemical Vapour Deposition of aluminium doped zinc oxide films

“…[37,[42][43][44]. Tang et al [45] and Fragal et al [46] reported the relationship between optical band gap and Al doping concentration of the ZnO thin films. They observed that in un-doped ZnO films, the optical band gap appeared at 3.25 eV while it increased to 3.47 eV with Al doping.…”

Thickness study of AZO films by RF sputtering in Ar + H2 atmosphere at room temperature

“…Al‐doped ZnO thin films can be prepared by different technologies such as sol‐gel, spray pyrolysis, pulsed laser deposition (PLD), magnetron sputtering, and metalorganic chemical vapor deposition (MOCVD) 6–10. Among these techniques, magnetron sputtering is the most commonly used method because it is a low‐cost, simple, and safe method and it can produce high deposition rates at low temperature and obtain highly uniform and larger scale films with high packing density and strong adhesion 11.…”

Integration of Metal Organic Chemical Vapour Deposition and Wet Chemical Techniques to Obtain Highly Ordered Porous ZnO Nanoplatforms

“…13 Ar (250 sccm) and O 2 (250 sccm) were used as carrier and reaction gases, respectively and the total pressure in the reactor was about 5 Torr. Depositions were carried out for 1 hour min and the deposition temperature is 600 C. After that, polystyrene (PS, Aldrich) microbeads of 1 micron of diameter were deposited onto the seed layers by drop casting and allowed to self-assemble in ordered close-packed colloidal monolayers.…”