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Transparent photovoltaic (TPV) devices have the potential to revolutionize photovoltaic (PV) technology by enabling on‐site generation while minimizing visual impact. However, a major challenge in the development of TPV, as well as for many PV technologies, is the open‐circuit voltage (Voc) deficit, which limits their efficiency. In this work, the development of wide‐bandgap inorganic‐based TPV devices is reported with a focus on low‐cost, earth‐abundant, stable, and nontoxic materials. The device structure consists of an ultrathin hydrogenated amorphous silicon (a‐Si:H) absorber and metal‐oxide layers as selective contacts. Herein, novel approach is presented to significantly improve device performance, especially in Voc, by introducing molecular dipoles in the device electron‐transport layer. By incorporating polyethyleneimine or poly(amidoamine) G1 and G2 dipoles, Voc (from 410 mV up to 638 mV) is significantly increased without sacrificing the average photopic transmittance of the device, leading to a record efficiency for this particular approach in TPV. Measurements confirm excellent long‐term stability. This approach can potentially allow tuning the work function of the selective contacts enabling the use of low‐cost, earth‐abundant materials that are not optimized for a particular absorber. Furthermore, this solution circumvents the issue of low Voc by a simple interface treatment. [ABSTRACT FROM AUTHOR]

Van der Waals chalcogenides and chalcohalides have the potential to become the next thin film PV breakthrough, owing to the earth-abundancy and non-toxicity of their components, and their stability, high absorption coefficient and quasi-1D structure, which leads to enhanced electrical anisotropic properties when the material is oriented in a specific crystalline direction. However, quasi-1D semiconductors beyond Sb2(S,Se)3, such as SbSeX chalcohalides, have been scarcely investigated for energy generation applications, and rarely synthesised by physical vapor deposition methodologies, despite holding the promise of widening the bandgap range (opening the door to tandem or semi-transparent devices), and showing enticing new properties such as ferroelectric behaviour and defect-tolerant nature. In this work, SbSeI and SbSeBr micro-columnar solar cells have been obtained for the first time by an innovative methodology based on the selective halogenation of Sb2Se3 thin films at pressure above 1 atm. It is shown that by increasing the annealing temperature and pressure, the height and density of the micro-columnar structures grows monotonically, resulting in SbSeI single-crystal columns up to 30 μm, and tuneable morphology. In addition, solar cell prototypes with substrate configuration have shown remarkable Voc values above 550 mV and 1.8 eV bandgap. [ABSTRACT FROM AUTHOR]

High open-circuit voltage in Sb2Se3 thin-film solar cells is a key challenge in the development of earth-abundant photovoltaic devices. CdS selective layers have been used as the standard electron contact in this technology. Long-term scalability issues due to cadmium toxicity and environmental impact are of great concern. In this study, we propose a ZnO-based buffer layer with a polymer-film-modified top interface to replace CdS in Sb2Se3 photovoltaic devices. The branched polyethylenimine layer at the ZnO and transparent electrode interface enhanced the performance of Sb2Se3 solar cells. An important increase in open-circuit voltage from 243 mV to 344 mV and a maximum efficiency of 2.4% was achieved. This study attempts to establish a relation between the use of conjugated polyelectrolyte thin films in chalcogenide photovoltaics and the resulting device improvements. [ABSTRACT FROM AUTHOR]

Development of carrier selective contacts for crystalline silicon solar cells has been recently of great interest toward the further expansion of silicon photovoltaics. The use of new electron and hole selective layers has opened an array of possibilities due to the low‐cost processing and non‐doping contacts. Here, a non‐doped heterojunction silicon solar cell without the use of any intrinsic amorphous silicon is fabricated using Deoxyribonucleic acid (DNA) as the electron transport layer (ETL) and transition metal oxide V2O5 as the hole transport layer (HTL). The deposition and characterization of the DNA films on crystalline silicon have been studied, the films have shown a n‐type behavior with a work function of 3.42 eV and a contact resistance of 28 mΩ cm2. This non‐doped architecture has demonstrated a power conversion efficiency of 15.6%, which supposes an increase of more than 9% with respect to the cell not containing the biomolecule, thus paving the way for a future role of nucleic acids as ETLs. [ABSTRACT FROM AUTHOR]