Characteristics of c-axis oriented large grain ZnO films prepared by low-pressure MO-CVD method

Abstract Polycrystalline ZnO (0 0 0 2) films with large grains were prepared by low-pressure MO-CVD of zinc acetylacetonate (Zn(C 5 H 7 O 2 ) 2 ) and oxygen. The films were deposited on Corning glass substrates at substrate temperatures between 475 and 540 °C. The size of the grains estimated from atomic force microscope patterns was as large as 200 nm. Room temperature photoluminescence (PL) spectrum of the films exhibits only a strong peak consisted of near-band edge emission at 378.8 nm. Low temperature (4.2 K) PL spectrum exhibits an emission from bound exciton of nature donors. The resistivity of the films critically depends on the amount of dopant, and changes in a range of 10 −2 –10 −4 Ω cm. The lowest resistivity of 6.9×10 −4 Ω cm was obtained in the Ga-doped films. The electron concentration and Hall mobility of the film with the lowest resistivity are 2.2×10 20 /cm 3 and 40.9 cm 2 /V s, respectively.