Aligned Al:ZnO nanorods on Si with different barrier layers for optoelectronic applications

• Published in: Chemical physics letters Vol. 534; pp. 48 - 53
• Main Authors: Holloway, Terence, Mundle, Rajeh, Dondapati, Hareesh, Bahoura, M., Pradhan, A.K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2012
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2012.03.028

[Display omitted]
► Vertically aligned ZnO nanorod arrays synthesized hydrothermally at low temperature. ► Several barrier layers introduced to form the pin diode to reduce the leakage current. ► Significant reduction of photocurrent in arrays on AZO/SiO2/p-Si heterojunction. ► The reduction of photocurrent related to multiple light scattering. ► This research opens venues for optoelectronics with desirable aligned nanostructures.
We report almost perfectly vertically aligned ZnO nanorod arrays synthesized by the hydrothermal route at considerably lower temperature on a sputtered Al:ZnO seed layer using different growth strategies. The nanorod arrays demonstrate remarkable alignment along the c-axis over a large area. Several barrier layers, such as ZnO, Al2O3, BaTiO3 and SiO2, were introduced to form the p-i-n junction to reduce the leakage current. The photocurrent is significantly reduced in nanorod arrays on AZO/SiO2/p-Si heterojunction due to multiple scattering phenomena from ZnO hexagonal facets associated with the nanorod arrays. This research may open up venues for various optical and opto-electronic applications where highly aligned nanostructures are desired.