In: Materials Science Research Trends ISBN: 978-1-60021-654-1 Editor: Lawrence V. Olivante, pp. 1-116 © 2007 Nova Science Publishers, Inc. Chapter 1 P-TYPE TRANSPARENT SEMICONDUCTING DELAFOSSITE CUALO 2+X THIN FILM: PROMISING MATERIAL FOR OPTOELECTRONIC DEVICES AND FIELD-EMISSION DISPLAYS Arghya N. Banerjee 1,a and Kalyan K. Chattopadhyay 2,b 1 Nanoscale Device Research, Department of Electrical and Computer Engineering, University of Nevada, Las Vegas, Nevada-89154, US. 2 Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata-700032, India. Abstract Copper based delafossite transparent semiconducting oxide thin films have recently gained tremendous interest in the field of optoelectronic technology, after the discovery of p- type conductivity in a transparent thin film of copper aluminum oxide (CuAlO 2 ). Most of the well-known and widely used transparent conducting oxide thin films such as ZnO, SnO 2 , ITO etc. and their doped versions are n-type material, but corresponding p-type transparent conducting oxides were surprisingly missing for a long time until the fabrication of above- mentioned p-CuAlO 2 thin film have been published (Nature 1997, 389, 939). This has opened up a new field in opto-electronics device technology, the so-called “Transparent Electronics”, where a combination of the two types of transparent conducting oxides in the form of a p-n junction could lead to a ‘functional’ window, which transmits visible portion of solar radiation yet generates electricity by the absorption of UV part of it. Non-stoichiometric and doped versions of various new types of p-type transparent conducting oxides with improved optical and electrical properties have been synthesized in the last few years in this direction. Wide range of deposition techniques have been adopted to prepare the films. But fabrication of device quality films by cost-effective deposition techniques such as sputtering, chemical vapor deposition, wet-chemical dip-coating technique etc. are the need of the hour for large-scale production of these films for diverse device applications. Here we have discussed the fabrication and opto-electrical characterization of p-CuAlO 2+x thin films by cost-effective and a E-mail address: banerjee_arghya@hotmail.com;arghya@egr.unlv.edu (Arghya N. Banerjee, corresponding author) b E-mail address: kalyan_chattopadhyay@yahoo.com (Kalyan K Chattopadhyay)