Optoelectronics Reports

In the quest for sustainable energy solutions, we undertook a rigorous examination of both toxic and non-toxic perovskite solar cells (PSCs), assessing their potential across different absorber thicknesses and their viability within Building-Integrated Photovoltaics (BIPV). Our MAPbI₃-based solar cell, utilizing TiO₂ and Cu₂O as electron and hole transport layers, respectively, exhibited an efficiency of 20.65% with a 400 nm opaque absorber. Interestingly, when this thickness was reduced to 200 nm, endowing the PSC with semitransparent properties, certain performance metrics altered, revealing insights crucial for BIPV integration. Further experiments with the toxic FAPbI₃ absorber resulted in an efficiency of 23.37% for its 400 nm opaque variant. However, the semitransparent 200 nm layer presented distinct characteristics, emphasizing the complex interplay between thickness, transparency, and efficiency. Our exploration did not stop at toxic materials; we delved into non-toxic alternatives, MAGeI₃ and RbGeI₃. These variants produced efficiencies of 14.59% and 20.40% for their 400 nm configurations. Yet again, their 200 nm semitransparent counterparts showcased performance nuances. Synthesizing our findings, it becomes evident that semitransparent PSCs hold significant promise for BIPV applications, but achieving an optimal blend of efficiency, transparency, and architectural appeal demands further focused research.

It is expected that the physical paradigm of solar cells will be possible to fabricate optical biosensors that mimic the human eye, including flexibility and stretchability. The purpose of this article is to demonstrate the morphological fabrication of an optical biosensor made of rubber by utilizing the physical paradigm of solar cells involving electric and chemical processes. However, a critical problem of current solar cells is their use of pieces of solid transparent conductive glass as electrodes, as especially shown in organic thin-film type solar cells involving dye-synthesized and perovskite-type solar cells. Therefore, we must solve this problem in order to be able to develop flexible and stretchable solar cells for optical biosensors. The key point of the solution is to avoid using rigid conductive glass and to coat a flexible and stretchable material such as rubber with TiO₂. In the present study, we proposed a novel fabrication technique for a flexible and stretchable rubber coated with TiO₂ by electrolytic polymerization utilizing our developed magnetic responsive intelligent fluid, hybrid fluid (HF), in order to produce the optical biosensor. The photovoltaic results experimentally demonstrated the photovoltage response to illumination with around 3–60 mV enhancement. In addition, we elucidated the photovoltaic mechanism by using electrochemical measurement involving the cyclic voltammetry (CV) profile and electrochemical impedance spectroscopy (EIS), introducing the equivalent electric circuit's intrinsic structure. The results demonstrated that the rubber type behaves dominantly in the area outside the electrical double layer (EDL) under illumination, and then the response time of photovoltage to illumination is slow with non-linear CV profiles. On the other hand, the optical biosensor type behaves dominantly in the EDL under illumination, and then the response time is fast with linear CV profiles, which denotes that the optical biosensor type is optimal for photodiodes. Furthermore, these results can demonstrate the chemical-photovoltaic reaction of the HF rubber involving TiO₂. The investigation might present the viability of the fabrication of ophthalmological systems that mimic the human eye.