Figure 2.

a SEM image of ZnO NTs b low-resolution TEM image of single ZnO NT showing the tubular structure with etching depth. The inset is a high-resolution TEM showing the single-crystalline structure of the ZnO NTs

Sadaf et al. Nanoscale Research Letters 2010 5:957-960   doi:10.1007/s11671-010-9588-z