An Overview of High‐Performance Indoor Organic Photovoltaics

Abstract

In recent years, indoor organic photovoltaics (IOPVs) have attracted increasing attention because of their ability to power microelectronic devices and sensors, especially for the internet of things (IoT). In contrast with silicon‐based indoor PV, the IOPVs exhibit better performance due to their tunable bandgap via molecular design, which could achieve a better spectrum matched with the lighting sources. Based on the simulated power conversion efficiency (PCE) in theory, the maximum value can achieve over 50 % under the white LED illumination, which is much higher than the practical top PCE of 31 %, indicating there is room further to improve the performance of IOPVs by various optimization methods. Based on these benefits, the recent progress in IOPVs with different methods was summarizes, and light was shed on the remaining challenges for achieving practical applications in the future. In the end, some guidelines for the development of IOPVs were proposed.

Machine Learning-Assisted Development of Organic Solar Cell Materials: Issues, Analyses, and Outlooks

“…Organic photovoltaics (OPVs), which are made up of a bulk heterojunction (BHJ) thin film of positive (p-) and negative (n-) type π-conjugated polymers and/or molecules, constitute an exceptionally rich area of research toward the implementation of nontoxic, lightweight, and cost-effective next-generation solar cells. − The power conversion efficiency (PCE) of OPVs has increased from the initial ∼1% for the p/n bilayer device, ∼4% for the BHJ of a homopolymer (e.g., regioregular poly­(3-hexylthiophene)) and a soluble fullerene acceptor (FA) such as [6,6]-phenyl-C 61 (or C 71 )-butyric acid methyl ester (PCBM), ∼11% for donor (D)–acceptor (A) narrow bandgap polymers (NBPs) and PCBM, to >18% of polymer and nonfullerene acceptor (NFA). − While many of the OPVs focus on the single-junction BHJ of p-type polymer and n-type FA (or NFA), the recent rapid progress in all-polymer BHJs (p-type polymer and n-type polymer), − ternary blends (p,p,n or p,n,n composed of three kinds of polymers and molecules) achieving 19% PCE, − and tandem cells , are also notable. In addition to the large freedom of chemical structures of D–A polymers and A–D–A NFAs, an appropriate choice of their side solubilizing alkyl chains has a significant impact on BHJ formation during the wet process and therefore the PCE of the devices. − Rigorous optimization of the wet process (e.g., solvent, high boiling temperature additive, thermal annealing, and vapor annealing) and device structure (normal/inverted structures, hole/electron transport layer, and thickness of each layer) is required after the material synthesis.…”

Advances in Organic and Perovskite Photovoltaics Enabling a Greener Internet of Things

“…method is not ideal, they suggested slot-die or blade coating along with using a module strategy with several smaller cells connected in series, rather than having one large area cell. [46] The power output of the PV is of crucial importance when considering PVs as power sources for the IoT. It is noteworthy that the power-per-weight has been identified as a critical figure of merit to evaluate PVs, which should be always reported.…”

“…Finally, for large scale fabrication of iOPVs, since spin coating as the deposition method is not ideal, they suggested slot‐die or blade coating along with using a module strategy with several smaller cells connected in series, rather than having one large area cell. [ 46 ]…”

Optimizing the Photovoltaic Performance of Organic Solar Cells for Indoor Light Harvesting

“…[1][2][3] The outstanding performance of OSCs under weak light illumination makes them especially suited for self-sustainable indoor electronic devices, urgently needed for the emerging industries including Internet of Things. [4][5][6] The power conversion efficiency (PCE) of OSCs under standard solar illumination (AM 1.5G) has been increased to over 18 %, with the short-circuit current density (J SC ) over 25 mA cm À 2 . [7][8][9] Also, semitransparent organic solar cells, with great potential for power window applications, have been demonstrated to deliver PCEs over 13 %.…”

“…Thanks to the unique advantages of mechanical flexibility, low weight, semitransparent property, and solution processability, organic solar cells (OSCs) based on a bulk‐heterojunction (BHJ) concept have great potential as a next‐generation photovoltaic (PV) technology [1–3] . The outstanding performance of OSCs under weak light illumination makes them especially suited for self‐sustainable indoor electronic devices, urgently needed for the emerging industries including Internet of Things [4–6] …”