![]() ![]() Their peculiar optical characteristics have resulted in various applications such as light-emitting diodes (LED), ,, solar cells, ,, and bio imaging. Although they present synthetic difficulties due to their covalent bonding character, the potential for opto-device applications is immense because of their high photoelectron efficiency. Among the possible substitutes, III–V QDs are widely valued because of their large Bohr radius and good quantum confinement effects. Meanwhile, cadmium toxicity has recently emerged as an issue, and thus alternatives to CdSe QDs, the most frequently used QDs, are urgently needed. Notably, fabrication is usually based on modification of the structure, including alloying, core/shell fabrication, and doping. Therefore, intensive research has been performed on the fabrication of QDs, and their properties and applications have been investigated. We then fabricated QD-based solar cells and investigated the cell properties, obtaining an open-circuit voltage ( V OC) of 0.51 V, a short-circuit current density ( J SC) of 12.4 mA/cm 2, and a fill factor (FF) of 44% the efficiency of 2.7% shows an improvement of more than 50% as compared to the values in previous reports.Ĭolloidal semiconductor nanocrystals (i.e., quantum dots, QDs) have received much attention because their absorption and emission properties are controlled by their sizes. The particle size increased from 2.6 nm to 5 nm, whereas the absorption and emission spectra exhibited a slight red shift, which is typical of type-I structured core/shell QDs. We characterized the QDs by powder X-ray diffraction, transmission electron microscopy, and absorption and emission spectroscopy. We synthesized type-I InAs/ZnSe core/shell QDs as an effective solution they are expected to have enhanced solar cell efficiency because of the different wettability of the ZnSe shell and their superior stability as compared to that of the unstable InAs core. However, poor coverage of the titania layer causes a low solar efficiency of ∼1.74%. InAs nanocrystals have a narrow band gap of 0.38 eV, a high absorption coefficient, and multiple exciton generation hence, they are promising candidates for application in solar cells. These findings present a promising alternative to SK-QDs as intermediate band in photovoltaic applications. Moreover, different coverages of SML InAs have been tested for optimum performance improvement of solar cell and near 0.25 ML InAs deposition was found best for solar cell application. In a comparison of performance, the SML-QD sample delivered superior performance (Almost 23% relative efficiency improvement compared to reference SC) compared to the other devices. SCs with different quantum structures, such as, Stranski-Krastanov (SK) quantum dots (QDs), quantum well (QW), submonolayer (SML) QDs (0.25 ML, 0.5 ML and 0.75 ML) and a quasi-monolayer (1 ML) InAs stack, were fabricated while keeping the total InAs content the same in all SCs. The effect of different quantum structures in the intrinsic region of a pin junction solar cell (SC) on the optical and electrical properties have been investigated. ![]()
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