Bandwidth density optimization of misaligned optical interconnects

In this paper, the bandwidth density of misaligned free space optical interconnects (FSOIs) system with and without coding under a fixed bit error rate is considered. In particular, we study the effect of using error correction codes of various codeword lengths on the bandwidth density and misalignment tolerance of the FSOIs system in the presence of higher order modes. Moreover, the paper demonstrates the use of the fill factor of the detector array as a design parameter to optimize the bandwidth density of the communication. The numerical results demonstrate that the bandwidth density improves significantly with coding and the improvement is highly dependent on the used codeword length and code rate. In addition, the results clearly show the optimum fill factor values that achieve the maximum bandwidth density and misalignment tolerance of the system.

Face-On Oriented Hydrophobic Conjugated Polymers as Dopant-Free Hole-Transport Materials for Efficient and Stable Perovskite Solar Cells with Fill Factor Approaching 85%

Developing high-performance dopant-free hole transport material (DF-HTM) is critical to realizing stable perovskite solar cells (PSCs). Herein, a class of siloxane-terminated polymers (PBZ-Si) with low surface energy were studied as...

Grey Wolf Optimizer-Based Array Reconfiguration to Enhance Power Production from Solar Photovoltaic Plants under Different Scenarios

The extraction of maximum power is a big challenge in solar photovoltaic-based power plants due to varying atmospheric and meteorological parameters. The concept of array reconfiguration is applied for the maximum power extraction in solar PV plants. Using this approach, the occurrence of multiple peaks in P-V and I-V characteristics during partial shade can be smoothened and reduced significantly. Partial shading due to the movement of the cloud is considered in the research. The cloud movement mainly because of velocity and wind direction is used for creating various shading conditions. The main focus is to reduce the power losses during partial shading using a nature-inspired optimization approach to reconfigure the array for different types of shading conditions. A grey wolf optimizer-based bridge-linked total cross-tied (GWO-BLTCT) configuration is proposed in this paper. The performance of the proposed topology is compared with standard and hybrid topologies, namely, series-parallel, total cross-tied, BLTCT, and SuDoKu-BLTCT, based on performance indicators such as fill factor, performance ratio, power enhancement, and power loss. The proposed GWO-BLTCT outperforms the remaining topologies due to the least power loss and high fill factor. It also has the highest average power enhancement and performance ratio with 23.75% and 70.02% respectively.

Simultaneous measurement of photocurrent and recombination emission in organic solar cell

Charge transfer (CT) state is a key intermediate to understand recombination processes in organic solar cells (OSCs). In this study, we measured the recombination emission from the CT state under different applied voltages in OSCs and a photocurrent density flowing on the circuit simultaneously. We proposed a “photoluminescence (PL)–voltage (V) plot” that is the voltage dependence of PL intensity of the CT state. The PL–V plot includes information only from the CT state recombination at the donor/acceptor interface and is complementary to the “current density (J)–V plot” that is the most important information for evaluating OSCs. The results demonstrated that fill factor (FF) of the PL–V plot is higher than that of the J-V plot, predicting the ideal FF of the device. Our result demonstrated that the simultaneous measurement of photocurrent and recombination emission could be a strong tool for evaluating photoconversion characteristics in OSCs.