Optical and current transport properties of CuO/ZnO nanocoral p–n heterostructure hydrothermally synthesized at low temperature

Abstract

We demonstrate the synthesis, and investigate the electrical and optical characteristics of "nanocorals" (NCs) composed of CuO/ZnO grown at low temperature through the hydrothermal approach. High density CuO nanostructures (NSs) were selectively grown on ZnO nanorods (NRs). The synthesized NCs were used to fabricate p-n heterojunctions that were investigated by the current density-voltage (J-V) and the capacitance-voltage (C-V) techniques. It was found that the NCs heterojunctions exhibit a well-defined diode behavior with a threshold voltage of about 1.54 V and relatively high rectification factor of ~ 760. The detailed forward J-V characteristics revealed that the current transport is controlled by an ohmic behavior for V ≤ 0.15 V, whereas at moderate voltages 1.46 ≤ V < 1.5 the current follows J α exp (βV) relationship. At higher voltages (≥ 1.5 V) the current follows the relation J α V 2 , indicating that the space-charge-limited current mechanism is the dominant current transport. The C-V measurement indicated that the NCs diode has an abrupt junction. The grown CuO/ZnO NCs exhibited broad light absorption range that is covering the UV and the entire visible part of the spectrum.

Selective growth of ZnO nanorods on microgap electrodes and their applications in UV sensors

“…The seeded area was completely covered with ZnO nanorods which indicates selective growth on the area of microgap electrodes. It is noteworthy to mention that the as-grown ZnO nanorods were interconnected to each other as noticeably seen by the SEM observations [29-31]. Such interconnected network facilitates electron transport along the nanorod/nanowire axis [32,33].…”

Effect of bath concentration on the growth and photovoltaic response of SILAR-deposited CuO thin films

“…The oxides of copper such as cuprous oxide (Cu 2 O) and cupric oxide (CuO) are the two stable forms of semiconducting oxides having different crystal structures and physical properties [8,9]. The Cu 2 O has been widely studied as an absorber for low-cost solar cells [10][11][12][13][14], but its high optical band gap (2.1 eV) is not optimum to obtain high conversion efficiency in single-junction solar cells [15], whereas the CuO possesses a direct band gap of *1.3 eV, which is ideal for an absorber material to be used in solar cell applications [16,17].…”

Design of p-CuO/n-ZnO heterojunctions by rf magnetron sputtering

“…CuO can be implemented into heterojunctions that are used for gas sensing , photocatalysis , self‐cleaning , thin film transistors and recently reported solar cell . The CuOZnO heterostructure has been investigated frequently because it can be fabricated in the form of thin films or nanocomposites by solution , gas‐phase or direct bonding techniques.…”