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Zinc oxide nanorods (ZnO NRs) have gained considerable research interest due to their robust energy conversion efficiency. In the present work, ZnO NRs arrays were pinpointed to probe their electromechanical response under strain conditions. ZnO seed was sputtered on different substrates by radio frequency magnetron sputtering (RF) technique at 80 W constant power and 3.49 × 10−5 mbar base pressure. The X-ray diffraction patterns exhibit hexagonal wurtzite structure with preferred c-axis crystal directions in the (002) plane. The average thickness of the seed layer for all the samples was estimated at around 214.6 nm. Surface roughness and morphologies of the nanorods have been characterized by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), respectively. FE-SEM images show homogeneous growth in different directions on substrates. The average diameters of ZnO NRs on silicon, glass and ITO were 51, 58 and 61 nm, respectively. The average length of all the nanorods on the substrates were measured around 1–2 μm. The local piezoresponse measurements conducted on two selected domain regions of the nanorod arrays had been characterized by piezoresponse force microscopy (PFM) to confirm the switching-piezoelectric behavior.

Zinc oxide (ZnO) nanorods have attracted considerable attention in recent years owing to their piezoelectric properties and potential applications in energy harvesting, sensing, and nanogenerators. Piezoelectric energy harvesting-based nanogenerators have emerged as promising new devices capable of converting mechanical energy into electric energy via nanoscale characterizations such as piezoresponse force microscopy (PFM). This technique was used to study the piezoresponse generated when an electric field was applied to the nanorods using a PFM probe. However, this work focuses on intensive studies that have been reported on the synthesis of ZnO nanostructures with controlled morphologies and their subsequent influence on piezoelectric nanogenerators. It is important to note that the diatomic nature of zinc oxide as a potential solid semiconductor and its electromechanical influence are the two main phenomena that drive the mechanism of any piezoelectric device. The results of our findings confirm that the performance of piezoelectric devices can be significantly improved by controlling the morphology and initial growth conditions of ZnO nanorods, particularly in terms of the magnitude of the piezoelectric coefficient factor (d33). Moreover, from this review, a proposed facile synthesis of ZnO nanorods, suitably produced to improve coupling and switchable polarization in piezoelectric devices, has been reported.

Dynamic integration of aligned nanostructures fabricated on different surfaces has prompted the needs for a novel nanoelectromechanical energy harvester. This study describes the morphologies of as-synthesized zinc oxide (ZnO) nano rod-like structures grown onto a bare sputtered substrate and patterned microcontact electrode (IDE), using a simple chemical bath deposition method (CBD). Local piezoresponse measurements were conducted to detect the piezoelectric response and polarization switching in Zinc oxide nanorods. The morphological characteristics and electromechanical response of the grown nanostructures on the printed electrode have been investigated, as a step towards enhancing the performance of piezoelectric nanogenerators. The growth characteristics and energy harvesting ability of nanostructured ZnO on interdigitated microelectrode (IDE) were reported. AFM analysis indicated that the average seed layer thickness of the ZnO film deposited before the lithographic pattern of the IDE was about ~267.5 nm. The FESEM images and XRD analysis confirmed that the ZnO nanorods possessed a hexagonal wurtzite structure having the c-axis crystal orientation preferentially in the (002) plane. FTIR spectrum confirmed the secondary vibrations of the Zn–O bonding at 669.75 cm−1 even with the adjustment in the microstructural features of ZnO. Finally, the Piezoresponse Force Microscopy (PFM) analysis confirmed the converse piezoelectric response of the grown nanorods.

Indium antimonide nanowires were synthesized by electrochemical deposition using anodic aluminum oxide template in the presence of gold film as conductive layers. Field emission scanning electron microscopy and energy dispersive X-ray spectrometry measurements were carried out to investigate the effect of adhesive insulated tape covered below the conductive layer. Results showed that the anodic aluminum oxide template covered with insulating tapes had better morphology with less presence of overgrown rough film on the topside of the anodic aluminum oxide template and it exhibited a smoother nanowire sidewall as compared to the uncovered ones. Additionally, the unique properties of anodic aluminum oxide were controllable pore diameter with a narrow size distribution at some intervals. It was evident from the energy dispersive X-ray spectrum that the nanowires synthesized from the covered template condition exhibited better InSb composition and stoichiometric ratio compared to the uncovered template condition.

Concentrator photovoltaics (CPV) is of much intrigue among all photovoltaic (PV) technologies because it replaces the expensive PV cell material with cheaper optical concentrators and occupies less land area as compared with conventional PV technology. However, it is challenging to handle the elevated operating temperature of CPV cells, which is reported capable of deteriorating the lifetime and power conversion efficiency of the CPV system. The integration of a CPV system with thermoelectric generators (TEG) provides a state-of-the-art hybrid design for improving energy harnessing from both electrical and thermal outputs, which also implies a better utilization of solar energy. This review article delineates various integration options of the CPV-TEG system and up-to-date developments of different configurations of hybrid CPV-TEG system including CPV-TEG with a spectral beam splitter, CPV/thermal-TEG, and CPV-TEG with phase changing materials. The numerical simulation and experimental studies on various configurations of hybrid CPV-TEG systems are summarized and outlined in this review. It has been found that the integrated CPV-TEG based solar thermal systems have higher electrical and thermal performances than that of non-concentrated PV-TEG systems. Finally, some recommendations are made for the future development of CPV-TEG systems.

The increasing prevalence and miniaturization of electronic devices have driven global efforts to develop small-scale, self-sustaining, rugged, and ecologically viable power sources. Nanogenerators, with the ability to scavenge ambient energy from the environment, offer an elegant solution to this need for small-scale power sources. A major route of development for nanogenerators has been in integration with other green energy sources. This article discusses one such integrated power source, namely the photovoltaic and nanogenerator hybrid cells. These hybrid cells have come a long way in terms of mechanical integrity, power output, and efficiency since they were first reported in 2009. Each published instance of photovoltaic and nanogenerator hybrid cell is reviewed systematically and the salient points in each case have been discussed. The article has been concluded with a discussion on the current state of this technology, its limitations, and the avenues for future research.

We report our investigation on the growth of ZnO nanostructure on a patterned interdigitated microelectrode (IDE) using chemical bath deposition (CBD). Piezoresponse force microscopic techniques were used to characterise the piezoelectric material domain of the grown ZnO nanostructures. The synthesised ZnO nanostructures exhibits a hexagonal wurtzite structure with the c-axis preferred crystal orientation in the (002) plane. The average thickness of the ZnO seed layer was 467.5 nm, whereas the diameter and length of ZnO nanostructure were measured to be 2.73 µm and 6.96 µm respectively. The combine effect of Zinc nitrate and HTMA concentration and seed layer thickness are considered as the main reason for crystal morphology evolution. The ZnO nanostructures exhibited a phase switch of the response and hysteresis in the plot of phase versus dc voltage, as evidenced by the polarization exchanging of its ferroelectric behaviour. These results provide a fundamental understanding of piezoresponse ZnO nanostructure for future energy applications.

Previous researches have shown that characteristics of entrepreneurial leadership have influence organisational performance regardless of the organisational size. This paper was set to review the relationship of vision, innovation, proactiveness and risk-taking on Small Medium Enterprises (SMEs) performance. This resulted to the question that does entrepreneurial leadership (i.e vision, innovation, proactiveness and risk-taking) significantly relate to performance of SMEs? From the review of related literatures, the characteristics of entrepreneurial leadership which comprises of vision, innovation, proactiveness and risk-taking are the features that can be found in both leadership and entrepreneurship, their present in organisation setting may positively impact on organisational success, the SMEs. Thus, SMEs operators that are more exposed to setting a clear goal and have clear set of activities would performed credible well interm of increase in sales, customer patronage and many other constructs that are related to the performance. In the same vein innovative SMEs tend to also performed well because of their ability in launching of a new product or advancing the existing one as well as studying of the market environment. On a general note out of four characterstics of entrepreneurial leadership, vision and innovation are the most significant toward the good performance of SMEs organisation.

In this paper, we have investigated stable structural, electric and magnetic properties of manganese (Mn) atom adsorption on armchair hydrogen edge-terminated boron nitride nanoribbon (A-BNNRs) using first principles method based on density-functional theory with the generalized gradient approximation. Calculation shows that Mn atom situated on the ribbons of A-BNNRs is the most stable configuration, where the bonding is more pronounced. The projected density of states (PDOS) of the favored configuration has also been computed. It has been found that the covalent bonding of boron (B), nitrogen (N) and Mn is mainly contributed by s, d like-orbitals of Mn and partially occupied by the 2p like-orbital of N. The difference in energy between the inner and the edge adsorption sites of A-BNNRs shows that Mn atoms prefer to concentrate at the edge sites. The electronic structures of the various configurations are wide, narrow-gap semiconducting and half-metallic, and the magnetic moment of Mn atoms are well preserved in all considered configurations. This has shown that the boron nitride (BN) sheet covered with Mn atoms demonstrates additional information on its usefulness in future spintronics, molecular magnet and nanoelectronics devices.

In this study, the adsorption influence of two different metals, gallium (Ga) and arsenide (As) adatoms on the stabilities and electronic structure of single graphene layer has been systematically studied using first-principles pseudopotentials calculations within the framework of density functional theory (DFT). The generalized gradient approximation used is PW91 exchange-correlation functional. The results of our calculations reveal that the adsorption of Ga atom on graphene resulted in electron transfer mainly from p-orbital of the Ga adatom to graphene and subsequently, altered the electronic state of graphene by shifting the Fermi level away from Dirac point, up to ∼1.5 eV. Meanwhile, the d-orbitals of Ga adatom have spin polarization at the Fermi level where the minority spin d-orbitals are unoccupied. The As adatom was found to have larger adsorption energy value on H, B and T sites of graphene compared to Ga adatom. Thus, we described this energy difference as a result of the bonding configurations between both Ga and As atoms with carbon in the graphene structure. While B-site favored the adsorption of arsenic adatom, we found that the most favored adsorption site for Ga adatom on graphene is above H-sites.

SMEs, if fully developed, would be of benefit in alleviating poverty through wealth and job creation. Thus, developments of SMEs serve as panacea to unemployment. In a developing country like Nigeria, there are several socio-economic conditions impeding meaningful development despite many interventions and policy strategies. However, in Nigeria, SMEs face numerous problems associated with leadership and entrepreneurship. Therefore, this study is aimed to analyse the significant impact of vision, innovation, proactiveness and risk-taking on SMEs' performance in Kano, Nigeria. Descriptive survey research design was used in the study. SPSS 19 and AMOS software were employed to analyse the data. Structural equation modelling (SEM) version 20 was used to arrive at the results of the study. The findings of the research show that there is positive and highly significant impact of vision on SMEs performance, positive and significant impact of innovation on SMEs' performance. Lastly, the results also show negative and highly significant impact of risk-taking on SMEs' performance. The study indicates that for SMEs' organisation to succeed they must have a clear vision, innovative capacity and ability to take and manage risk.

Stable geometries, electronic and magnetic properties of low coverage vanadium (V) atoms adsorption on graphene sheet have been investigated by first principles calculations, using generalized gradient approximation. Calculation shows that center of the ring is energetically favorable for both V adatom and perpendicular dimer after relaxation. Moreover, the proportion of orbital contribution of C-V bonding are mainly dominated by 2pz orbital of C and partially occupied by the 3d like states of V. It is also found that the low coverage V atom adsorbed graphene system is metallic and magnetic, and has demonstrated additional hint on its usefulness in magnetic devices.