JPE Editor-in-Chief Sean Shaheen remarks on the growth of generative AI and its potential for advancing scientific knowledge and discovery.

This study reports experimental test results on a solar-pumped laser that utilizes composite YAG/Ce:Nd:YAG/YAG/rod with a diameter of 3 mm. We measured an output power of 8.5 W with optical-to-optical conversion efficiency of 1.43% in multimode operation when the laser was exposed to an incoming solar power of 593 W at an irradiance of 900 W/m2. The YAG/Ce:Nd:YAG/YAG composite laser rod withstood the severe conditions of solar end-pumping for several hours of testing without any negative effects or degradation of laser output over time. To interpret and comprehensively analyze the experimental results, we developed a simulation model based on our experimental setup and conducted calculations with taking into account thermal population of lower laser levels. Simulation calculations show that a small deviation from a straight line in the experimental input–output dependence is a consequence of the weak influence of thermal population of the lower laser levels. To compare with recent achievements with conventional laser rods of comparable sizes and to formulate some useful recommendations when using composite crystals in future studies, we carried out additional numerical experiments taking into account possible optimizations, which do not affect in any way the thermal load on the front part of the laser rod considered in this experiment. The numerical studies demonstrate that solar-to-laser power conversion efficiency of 4.0% is achievable with a 3 mm laser rod when the solar input power is about 600 W. We also discuss the influence of rod size and thermal effects on conversion efficiency. Based on the findings of this study, we conclude that employing laser media composed of a single or multirod system with a composite structure could potentially offer an optimal solution to the thermal challenges inherent in solar-pumped solid-state lasers.

Realizing an excellent spectral response by utilizing the ultraviolet parts of solar radiation is an important focus for enhancing the performance of photovoltaic cells (PCs). Pr3+ and Eu3+ ions co-doped multifunctional transparent GdPO4 glass-ceramic is successfully prepared using a conventional melting quenching technique. In GdPO4: Pr3+-Eu3+, ultraviolet to visible downshifting is realized via the remarkable energy transfer from Pr3+ to Eu3+ ions by bridge Gd3+ ions. Introducing the spectral conversion material by converting ultra-violet photons into visible photons is considered a very promising route; it can be applied to perovskite PCs by reducing the photo-degradation and enhancing the light harvesting, and it can be applied to hydrogenated amorphous-silicon carbide PCs by reducing the solar energy losses associated with spectral mismatch of the spectral response and energy. The development of downshifting Pr3+-Eu3+ co-doped glass-ceramics might open up a new approach to achieving a better performance of photovoltaic devices.

Semitransparent solar cells (ST-SCs) have emerged as a prominent energy harvesting technology that combines the benefits of transparency and light-to-electricity conversion. The biggest opportunities for ST-SCs lie in their integration as windows and skylights within energy-sustainable buildings or combining them with other solar cell technologies in tandem configuration. The performance of ST-SCs is mainly determined by the trade-off between the competing parameters of the capability to convert the light-to-electricity while allowing some part of it to pass through imparting transparency. Depending on the target application, the selection of ST-SCs is a tricky affair as some devices might offer high efficiency but compromise transparency and vice versa. In addition, this is again not helped by the fact that due to advancements in materials engineering, processing, and characterization, vastly different combinations of efficiency and transparency have been reported. So to quantify the performance of ST-SCs, we attempted and developed a figure-of-merit (FoM), which can be used as a tool that can help in analyzing and comparing the performance among various ST-SCs. The defined FoM focuses on the efficiency of the device, bifaciality factor, transmittance in the desired region, and that corresponding to 550 nm wavelength. Additionally, we have been shown how the proposed FoM can be correlated for tandem and building-integrated photovoltaics applications. Based on these resultant parameters, FoM is calculated and compared for different device architectures available in the literature. The proposed FoM shall serve as a meaningful guiding path to the researchers for the development of advanced ST-SCs.

The luminescent coupling (LC) effect is one of the strategies for further boosting the efficiency of multijunction solar cells by improving the current mismatch among subcells. This work examined the LC effect in III–V compound InGaP/GaAs/InGaAs inverted metamorphic triple-junction solar cell (IMM-3JSC) by the laser beam-induced current mapping characterization method. A strong LC effect in the bottom subcell of the IMM-3J sample was demonstrated with an LC yield of around 0.13 under 7 suns irradiance. In addition, by effectively homogenizing the LC effect, the bottom subcell of IMM-3JSCs may potentially gain a current density of ∼0.6 mA/cm2 at 10 suns irradiance.

A hemispherical shell shape is proposed for an organic photovoltaic cell structure, aiming at enhancing both light absorption and angular coverage. Three-dimensional finite element analysis method is used to study the absorption spectra within the hemispherical-shell-shaped active layer. The study reveals that the proposed structure can result in 66% and 36% of absorption improvements compared to a flat-structured device when the incoming light is transverse electric (TE)- and transverse magnetic (TM)-polarized, respectively. It is also learned that the proposed hemispherical shell structure has absorption improvement as high as 13% (TE) and 21% (TM) when compared to the previously reported semicylindrical shell structure. The angular coverage of the proposed structure is improved as well, reaching 81 deg (TE) and 82 deg (TM), which becomes quite useful for the wearable electronics applications where the incidence angle can vary in a random manner. These improvements can be attributed to better light coupling and guiding through the active layer made possible by the hemispherical shell shape of the device.