This paper describes the pulsed laser deposition (PLD) technology of making ZnO thin films free from deep level emission (a problem of conventionaly grown ZnO films). A visible broad peak (deep level emission) is often seen in the ZnO photoluminescence (PL) spectrum and also a sharp exciton peak. ZnO films PLD-grown on La-doped (0.5%) SrTiO3 substrates were compared with those grown on SrTiO3 substrates. When grown on La-doped SrTiO3 substrate, the deep level emission disappeared almost completely. Even when (LaSr)TiO3 film was inserted between the ZnO film and SrTiO3 substrate, deep level emission was suppressed to a large extent. Using the present result, we fabricated a NiO/ZnO/La1-xYSr1-xTiO3 structure and characterized it. (C) 2002 Published by Elsevier Science B.V.