Design and Simulation of GaAsN Based Solar Cell with AlGaAs Blocking Layer for Harvesting Visible To Near-Infrared Light

In the present study, the performance parameters of GaAsN dilute nitride-based semiconductor solar cell with and without AlGaAs blocking layers have been investigated in detail by Solar Cell Capacitance Simulator in one dimensional software program (SCAPS-1D). The thickness of absorber, buffer, and blocking layers are varied to achieve the improvement of open circuit voltage, short circuit current, fill factor, efficiency and also to optimize the device structure. The impact of doping and defect densities on the solar cell performance parameters have been analyzed minutely inside the absorber, buffer, and blocking layers. The solar cell thermal stability parameters are also investigated in the temperature region from 273K to 373K. The efficiency of 43.90% and 40.05% are obtained from the proposed solar cells with and without AlGaAs blocking layer, respectively. The present findings may provide insightful approach for fabricating feasible, cost effective, and efficient dilute nitride solar cell.

Optimizing the PMMA Electron-Blocking Layer of Quantum Dot Light-Emitting Diodes

Quantum dots (QDs) are promising candidates for producing bright, color-pure, cost-efficient, and long-lasting QD-based light-emitting diodes (QDLEDs). However, one of the significant problems in achieving high efficiency of QDLEDs is the imbalance between the rates of charge-carrier injection into the emissive QD layer and their transport through the device components. Here we investigated the effect of the parameters of the deposition of a poly (methyl methacrylate) (PMMA) electron-blocking layer (EBL), such as PMMA solution concentration, on the characteristics of EBL-enhanced QDLEDs. A series of devices was fabricated with the PMMA layer formed from acetone solutions with concentrations ranging from 0.05 to 1.2 mg/mL. The addition of the PMMA layer allowed for an increase of the maximum luminance of QDLED by a factor of four compared to the control device without EBL, that is, to 18,671 cd/m2, with the current efficiency increased by an order of magnitude and the turn-on voltage decreased by ~1 V. At the same time, we have demonstrated that each particular QDLED characteristic has a maximum at a specific PMMA layer thickness; therefore, variation of the EBL deposition conditions could serve as an additional parameter space when other QDLED optimization approaches are being developed or implied in future solid-state lighting and display devices.