High optical quality IZO (In 2Zn 2O 5) thin films by PLD – A novel development for III–V opto-electronic devices

Abstract

Extrinsic zinc oxide (heavily indium oxide doped), i.e., indium zinc oxide (In 2Zn 2O 5) (IZO) as novel transparent conducting oxide (TCO) thin films were grown by pulsed laser deposition (PLD) technique using Johnson Matthey “specpure” – grade 90% In 2O 3 mixed 10% ZnO (as commercial indium tin oxide (ITO) composition) pellets. The effects of substrate temperatures and heavy indium oxide incorporation on IZO thin film growth, optical transmission, absorption, reflection and photoluminescence were studied. As well as the feasibility of developing a novel high quality transparent oxide thin films was also studied simultaneously. Also, as a novelty merit we want to emphasize as a interesting physical effect that the average optical transmittance T% (max) ⩾95% of IZO thin films is rivals that of the most TCO films for this conductivity level (of the order of 10 3 Ω −1 cm −1). This is the first time that we have applied these PLD prepared IZO thin films to iso and hetero semiconductor–insulator–semiconductor (SIS) type solar cells as TCO coatings. The optical parameter values were calculated, diagrammatically enumerated and tabulated. From optical studies, we have observed that the films were act as highly anti-reflective (AR) coatings. From PL study, we have confirmed the purity and high electrical conductivity of the deposited thin films. Supplementary studies on surface, electrical, structural and internal morphology of thin film growth correlated with optical transmission, absorption, reflection and photoluminescence gives added advantages to this work.