Properties of excitons confined to potential fluctuations due to indium distribution in the wetting layer which accompany self-assembled InAs/GaAs quantum dots are reviewed. Spectroscopic studies are summarized including time-resolved photoluminescence and corresponding single-photon emission correlation measurements. The identification of charge states of excitons is presented which is based on results of a theoretical analysis of interactions between the involved carriers. The effect of the dots’ environment on their optical spectra is also shown.

The self-consistent optical-electrical-thermal-gain model of the oxide-confined edge-emitting diode laser has been used to simulate the room-temperature operation of the long-wavelength 1.3-µm quantum-dot (InGa)As/GaAs diode laser. The validityof the model has been verified using some experimental results for comparison. An impact of quantum-dot densityon laser operation characteristics as well as on temperature dependence of lasing threshold have been discussed.

Modern scintillator detectors act as an efficient tool for detection and measurement of ionizing radiations. ZnSe based materials have been found to be a promising candidate for scintillation applications. These scintillators show much-needed scintillation efficiency along with advantages such as high thermal and radiation stability, less-toxicity, non-hygroscopicity, emissions in the visible range and small decay time etc. Further, in quantum confinement regime, they show improvement in luminescent properties and size dependent emissions. In this review article, the attempt has been made to trace the progress of ZnSe based materials towards highly efficient quantum dot scintillators. Here, the fundamental process of scintillation has been explained. Factors such as doping, annealing, heavy ion irradiation which affects the scintillation response of ZnSe based scintillators have also been discussed. Method of synthesis plays a key role in optimization of quantum dot properties. Hence, it has been tried to trace the development in methods of synthesis of quantum dots. With optimized synthesis, we can extend applications of these highly efficient quantum dot scintillators for various scientific and industrial applications.

There is a high impact of the solar cells on energy manufacturing. For several years the energy efficiency was limited due to base-materials' structural and technological limits. High increase of energy harvesting of solar cells has been observed since the first solar cell based on dye-sensitized colloidal TiO₂ films occurred. One of the most promising solutions are used quantum dots (QD) for light energy conversion. In this paper, we described the use of selected characterization techniques for sandwich-type TiO₂/QD composites for a low-cost quantum dots' solar cell in the point of view of mass manufacturer of solar cells and research and development laboratory. Moreover, the increasing role of Raman spectroscopy and mapping for the TiO₂/QD was presented and compared with other necessity techniques for solar cell investigations such as ellipsometry, atomic force microscopy (AFM), and secondary ion mass spectrometry (SIMS).

The impact ionization in semiconductor materials is a process that produces multiple charge carrier pairs from a single excitation. This mechanism constitutes a possible road to increase the efficiency of the p-n and p-i-n solar cells junctions. Our study considers the structure of InN/InGaN quantum dot solar cell in the calculation. In this work, we study the effect of indium concentration and temperature on the coefficient of the material type parameter of the impact ionization process for a p(InGaN)-n(InGaN) and p(InGaN)- i(QDs-InN)-n(InGaN) solar cell. Next, we investigate the effect of perturbation such as temperature and indium composition on conventional solar cell’s (p(InGaN)-n(InGaN)) and solar cells of the third generation with quantum dot intermediate band IBSC (p(InGaN-i(QD-InN)-n(InGaN)) by analyzing their behaviour in terms of efficiency of energy conversion at the presence of the impact ionization process. Our numerical results show that the efficiency is strongly influenced by all of these parameters. It is also demonstrated that decreased with the increase of indium concentration and temperature which contributes to an overall improvement of the conversion efficiency.

In the past decade, there has been significant progress in development of the colloidal quantum dot (CQD) photodetectors. The QCD’s potential advantages include: cheap and easy fabrications, size-tuneable across wide infrared spectral region, and direct coating on silicon electronics for imaging, which potentially reduces array cost and offers new modifications like flexible infrared detectors. The performance of CQD high operating temperature (HOT) photodetectors is lower in comparison with detectors traditionally available on the global market (InGaAs, HgCdTe and type-II superlattices). In several papers their performance is compared with the semiempirical rule, “Rule 07” (specified in 2007) for P-on-n HgCdTe photodiodes. However, at present stage of technology, the fully-depleted background limited HgCdTe photodiodes can achieve the level of room-temperature dark current considerably lower than predicted by Rule 07. In this paper, the performance of HOT CQD photodetectors is compared with that predicted for depleted P-i-N HgCdTe photodiodes. Theoretical estimations are collated with experimental data for both HgCdTe photodiodes and CQD detectors. The presented estimates provide further encouragement for achieving low-cost and high performance MWIR and LWIR HgCdTe focal plane arrays operating in HOT conditions.