In the past decade, considerable efforts have been made to develop semi-transparent organic solar cells (ST-OSCs). Different materials and architectures were examined with the aim of commercializing these devices. Among these, the use of ternary active layers demonstrated great promise for the development of efficient semi-transparent organic solar cells with the potential for future applications, including but not limited to self-powered greenhouses and powered windows. Researchers seek alternative solutions to trade-off between the power conversion efficiency (PCE) and average visible transmittance (AVT) of ST-OSCs, with photoactive materials being the key parameters that govern both (PCE) and (AVT), as well as device stability. Several new organic materials, including polymers and small molecules, were synthesized and used in conjunction with a variety of techniques to achieve semi-transparent conditions. In this review paper, we look at the working principle and key parameters of semi-transparent organic solar cells, as well as the methods that have been used to improve the performance and stability of ternary-based semi-transparent organic solar cells. The main approaches were concluded to be spectral enhancement and increments in the transparency of the active layer through band gap tuning, utilizing novel organic semi-conductors, optical engineering, and the design architecture of the active layers.

In this paper, a new sensor structure is presented based on a printed circuit board (PCB) monopole antenna with operating frequency of f= 2 GHz. Numerical investigation was performed in order to determine the ethanol alcohol ratio in wine and isopropyl alcohol ratio in disinfectants (sanitizers). Finite Integration Technique (FIT) based commercial high-frequency electromagnetic solver CST Microwave Studio has been used for the simulation study. The loss tangent values and dielectric constants of the samples used in the current study were obtained by KEYSIGHT brand PNA-L N5234A Network Analyzer. The proposed sensor structure was able to greatly differentiate the ethanol alcohol content in the wine and the isopropyl alcohol content in the sanitizer through the return loss values and corresponding graphs. In the design of patch antenna, the electromagnetic permittivity ratios of the samples corresponding to the alcohol ratio and isopropyl ratio are considered and the antenna dimensions along with the working frequency were optimized accordingly. In the related frequency band, permittivity values corresponding to the ethanol alcohol and isopropyl alcohol ratios exhibit a linear variation and make the sensor design possible. According to the obtained results, it was found that the changes in the resonance frequency can be associated with ethanol alcohol and isopropyl alcohol ratio inside the samples. The change of ethanol alcohol amount and isopropyl alcohol in the liquid samples tested at the resonance frequency of patch antenna is proportional to the change in the resonance frequency and they are very close to a linear characteristic.