SPIE publishes accepted journal articles as soon as they are approved for publication. Journal issues are considered In Progress until all articles for an issue have been published. Articles published ahead of the completed issue are fully citable.
Transparent conductive materials (TCMs) with high p-type conductivity and broadband transparency have remained elusive for years. Despite decades of research, no p-type material has yet been found to match the performance of n-type TCMs. If developed, the high-performance p-type TCMs would lead to significant advances in a wide range of technologies, including thin-film transistors, transparent electronics, flat screen displays, and photovoltaics. Recent insights from high-throughput computational screening have defined design principles for identifying candidate materials with low hole effective mass, also known as disperse valence band materials. Particularly, materials with mixed-anion chemistry and nonoxide materials have received attention as being promising next-generation p-type TCMs. However, experimental demonstrations of these compounds are scarce compared to the computational output. One reason for this gap is the experimental difficulty of safely and controllably sourcing elements, such as sulfur, phosphorous, and iodine for depositing these materials in thin-film form. Another important obstacle to experimental realization is air stability or stability with respect to formation of the competing oxide phases. We summarize experimental demonstrations of disperse valence band materials, including synthesis strategies and common experimental challenges. We end by outlining recommendations for synthesizing p-type TCMs still absent from the literature and highlight remaining experimental barriers to be overcome.
A new generation of anode interlayers (AILs) has been introduced in recent years for improving the efficiency and stability of organic solar cell (OSC) devices. Electrode interlayer modification is a simple and effective way of enhancing OSC device performance. We used poly(vinyl pyrrolidone) (PVP) as an AIL modifier to alter molybdenum trioxide (MoO3) and vanadium pentoxide (V2O5) AILs in OSC devices and compared them with pure metal oxide AILs. Using this modification, average power conversion efficiencies were raised from 5.2 % ± 0.4 % to 6.0 % ± 0.3 % for OSCs with MoO3-based AILs, and from 6.2 % ± 0.1 % to 6.8 % ± 0.3 % for OSCs with V2O5-based AILs. Moreover, the PVP-metal oxide AILs also improved the overall device quality, producing a nanotextured morphology with good optical properties and favorable chemical composition. Beneficial wetting properties for interfacial adhesion between anode and active layer are observed using contact angle measurements. Overall, devices with PVP-modified metal oxide AILs showed promising results with greater device stability compared to pure metal oxide AIL-based OSC devices.
A photovoltaic (PV) panel operating in partial shading condition results in lowering its power efficiency. In a worst-case scenario, it can create a hotspot that can eventually cause a fire hazard. To address this issue, bypass diodes are connected across a group of PV cells having series-parallel (SP) configuration. Owing to the placement bypass diodes in the PV panel, it can circumvent unshaded PV cells. Hence, topologies such as total cross-tied (TCT), bridge link (BL), and honeycomb (HC) for PV panels are proposed besides SP to reduce the effect of partial shading. Each configuration demonstrated advantages over SP topology. However, many of these configurations lack a mechanism to isolate PV cells that are affected due to the hotspot. Recently developed complementary metal oxide semiconductor (CMOS)-embedded PV panel has been shown to offer many other benefits besides effectively dealing with shading conditions. We are comparing the performance of CMOS-embedded PV panel under various partial shading conditions with PV panel with fixed configuration topologies, such as SP, TCT, BL, and HC. SPICE-based equivalent PV modeling technique is used in this research to compare the maximum power generated in different topologies under changing partial shading conditions. Results show that CMOS-embedded PV panels are more efficient in coping with partial shading conditions compared to any other contemporary fixed topologies.