Time-delayed transformation of defects in zinc oxide layers grown along the zinc-face using a hydrothermal technique
2009 (English)In: JOURNAL OF APPLIED PHYSICS, ISSN 0021-8979, Vol. 105, no 12, 123510- p.Article in journal (Refereed) Published
A study of deep level defects in a hydrothermally grown, intrinsically n-type zinc oxide (ZnO) device has been carried out using conventional deep level transient spectroscopy (DLTS). Performed under variable measurement conditions, DLTS demonstrates two electron trap levels, E-1 (dominant) and E-2, with activation energies E-c-0.22 +/- 0.02 eV and E-c-0.47 +/- 0.05 eV, respectively. A time-delayed transformation of shallow donor defects zinc(interstitial) and vacancy(oxygen) (Zn-i-VO) into the E-1 level has been observed. While the x-ray diffraction measurements reveal that the preferred direction of ZnO growth is along the (10 (1) over bar0) plane, i.e., the (Zn-i-V-O) complex, it is assumed that the (Zn-i-V-O) complex is transformed into a zinc antisite (Zn-O) under favorable conditions. As a result, the free carrier concentration decreases with increasing trap concentration. Henceforth, the E-1 level exhibiting the increase in concentration is attributed to ZnO.
Place, publisher, year, edition, pages
2009. Vol. 105, no 12, 123510- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-20225DOI: 10.1063/1.3149800OAI: oai:DiVA.org:liu-20225DiVA: diva2:233822