Cross-section image of ZnO quasi-NRs prepared using different cycle's growth (multiple) process. (A) 1, (B) 2, (C) 3 and (D) 4 cycles. The growth solution used contained 10 mM of zinc salts and 36 mM of ammonia. The growth time for each cycle is 4 min. The scale bars are 100 nm.
Ali Umar et al. Nanoscale Research Letters 2011 6:564 doi:10.1186/1556-276X-6-564