FABRICATION OF GREEN AND ORANGE PHOTOLUMINESCENT, UNDOPED ZNO FILMS USING SPRAY-PYROLYSIS

Photoluminescent, undoped ZnO films have been fabricated using spray p yrolysis of zinc nitrate solution. The luminescent films had a polycry stalline hexagonal wurtzite type structure with no preferred orientati on. Photoluminescence intensity was critically dependent on substrate temperature during spray pyrolysis and on post-annealing temperature. Green, photoluminescent films possessed a porous structure while orang e films possessed a close packed granular morphology. Green luminescen ce appears to be due to oxygen vacancies in a layer just below the cry stallite surface. (C) 1998 American Institute of Physics. [S0003-6951( 98)05216-4].