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In this study, a laterally coupled device composed of a photodiode and a Si nanowires-field-effect transistor (NWs-FET) is constructed on a plastic substrate and the coupled device is characterized. The photodiode is made of p-type Si NWs and an n-type ZnO film. The Si NWs-FET is connected electrically to the photodiode in order to enhance the latter's photocurrent efficiency by adjusting the gate voltage of the FET. When the FET is switched on by biasing a gate voltage of -9 V, the photocurrent efficiency of the photodiode is three times higher than that when the FET is switched off by biasing a gate voltage of 0 V. [ABSTRACT FROM AUTHOR]

Silver doped zinc oxide nanowires (NWs) were synthesized on (0001) sapphire substrate by hot-walled pulsed laser deposition. Both enhancement mode and depletion mode NW field effect transistors (FETs) were fabricated. The shift of threshold voltage of silver doped zinc oxide NW FET was observed from 2.45 to -3.2 V depending on the diameter of NWs without any significant changes of the subthreshold swing, carrier concentration, and on/off ratios. We demonstrate that the transfer characteristics of silver doped zinc oxide NW FETs were closely related with the size of NW diameter and control the shift of threshold voltage. [ABSTRACT FROM AUTHOR]

We demonstrate a pn heterojunction diode constructed with a n-type ZnO nanowire (NW) and a p-type HgTe nanoparticle (NP) thin film on a SiO2/p-Si substrate. For the pn heterojunction diode, the rectifying characteristics of both the dark current and the photocurrent excited by 633 nm wavelength light were observed, but the photocurrent excited by 325 nm wavelength light possesses Ohmic characteristics. The optoelectronic characteristics of the pn heterojunction diode were compared with those of the ZnO NW and HgTe NP thin film composing it. [ABSTRACT FROM AUTHOR]

We construct a flexible pn heterostructured photodiode using a CdTe nanoparticle thin film and a single ZnO nanowire (NW) on a plastic substrate. The photocurrent characteristics of the flexible photodiode are examined under illumination with 325 nm wavelength light and the photocurrent efficiencies at bias voltages of +- 2.5 V are estimated to be 8.0 and 2.1 uA W [?] 1 under forward and reverse bias conditions, respectively. The photocurrent generation of the pn heterostructured photodiode is dominantly associated with the transport of the photogenerated charge carriers in the single ZnO NW. Furthermore, the operations of our flexible photodiode are investigated in the upwardly and downwardly bent states, as well as in the flat state. [ABSTRACT FROM AUTHOR]

Electrically driven lasing was demonstrated in light-emitting devices composed of n-ZnO and p-Si nanowires (NWs). The ZnO NWs were synthesized by thermal chemical vapor deposition and the Si NWs were formed by crystallographic wet etching of a Si wafer. The p-n heterojunction devices were constructed using the NWs by the direct transfer and dielectrophoresis methods. At an excitation current of 2 uA, the electroluminescence spectrum showed lasing behavior, and this phenomenon was explained by the ZnO-nanostructure-related cavity property. [ABSTRACT FROM AUTHOR]

Flexible electronic devices which are lightweight, thin and bendable have attracted increasing attention in recent years. In particular, solution processes have been spotlighted in the field of flexible electronics, since they provide the opportunity to fabricate flexible electronics using low-temperature processes at low-cost with high throughput. However, there are few reports which describe the characteristics of electronic devices on flexible substrates. In this study, we fabricated flexible thin-film transistors (TFTs) on plastic substrates with channel layers formed by the spin-coating of ZnO nanoparticles and investigated their electrical properties in the flat and bent states. To the best of our knowledge, this study is the first attempt to fabricate fully functional ZnO TFTs on flexible substrates through the solution process. The ZnO TFTs showed n-channel device characteristics and operated in enhancement mode. In the flat state, a representative ZnO TFT presented a very low field-effect mobility of 1.2 x 10[?]5 cm2 V[?]1 s[?]1, while its on/off ratio was as high as 1.5 x 103. When the TFT was in the bent state, some of the device parameters changed. The changes of the device parameters and the possible reasons for these changes will be described. The recovery characteristics of the TFTs after being subjected to cyclic bending will be discussed as well. [ABSTRACT FROM AUTHOR]

The transfer of charge carriers, photogenerated in nanoparticles (NPs), into a single nanowire (NW) is demonstrated in this study by conducting a careful comparison of the optoelectronic characteristics of a ZnO NW with ZnO NPs attached to its surface, a bare ZnO NW and a film of close-packed ZnO NPs. Under the illumination of an above-gap light, the photocurrent taken from the NW with the NPs is remarkably higher in magnitude than that obtained from the bare NW, although the photocurrent is substantially lower for the close-packed NPs. The presence of the absorption band of the NPs in the photoresponse spectrum taken from the NW with the NPs reveals that the transfer of the charge carriers photogenerated in the NPs into the NW dramatically enhances the magnitude of the photocurrent flowing in this NW. Nevertheless, during the transfer, the charge carriers experience trapping and detrapping at the interfaces of the NPs and the NW. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we demonstrate the photogating effects of p-type HgTe nanoparticles (NPs) on an n-type ZnO nanowire (NW). The photogating effects are due to the charge separation of the charge carriers photogenerated in the NPs under illumination and the subsequent accumulation of the photogenerated electrons in the pn junction of the NPs and the NW. The presence of the electrons in the junction reduces the current in the ZnO NW. The photogating effects are proved by the different photocurrent behavior of the ZnO NW to which the HgTe NPs are attached from that of a bare ZnO NW. In addition, the dependence of the photogating effects on the power of the incident light is discussed. [Copyright &y& Elsevier]