Abstract
Indoor organic photovoltaics (OPVs) are currently being investigated for small-scale energy generation from artificial light sources to power small electronic devices. Despite recent progress in increasing the power conversion efficiency (PCE) of indoor OPVs, the widespread use of expensive indium tin oxide (ITO) as a transparent conducting electrode (TCE) leads to long energy payback times. This study provides a novel and comprehensive description of low-temperature atomic layer deposition (ALD)-processed indium-free tin dioxide (SnO2) films as inexpensive and efficient TCEs for indoor OPVs. These highly conformal and defect-free ALD-fabricated SnO2 films are applied to a poly(3-hexylthiophene):indene-C60 bisadduct-based OPV system. Under 1 sun illumination, an OPV with an SnO2 TCE exhibits limited operational capacity because of the high sheet resistance (~98 Ω sq−1) of the SnO2 layers. However, under a light-emitting diode (LED) lamp with a luminance of 1000 lx, the series resistance, which is related to the sheet resistance, has a marginal effect on the performance of the indoor OPV system, showing a PCE of 14.6 ± 0.3%. A reference OPV with an ITO TCE has a slightly lower PCE of 13.3 ± 0.8% under the same LED conditions. These results suggest that SnO2 TCEs can be efficient and cost-effective replacements for ITO TCEs in indoor OPV systems.
Highlights
1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Introduction Recently, semipermanent indoor energy harvesting systems have been increasingly studied for powering lowpower indoor electronic devices, such as sensor network nodes used in the “Internet of Things” technology platform[1]
The reduction in the resistivity of the SnO2 thin films was attributed to the increase in carrier concentration
We evaluated the indoor performance of organic photovoltaics (OPVs) systems with atomic layer deposition (ALD)-synthesized SnO2 Transparent conducting electrodes (TCEs)
Summary
Semipermanent indoor energy harvesting systems have been increasingly studied for powering lowpower indoor electronic devices, such as sensor network nodes used in the “Internet of Things” technology platform[1]. The use of thermoelectric, piezoelectric, and photovoltaic (PV) devices show the most promise. PV harvesters are considered suitable for indoor use due to their high power conversion efficiency (PCE) and `. Regarding the indoor operation of OPVs, conventional approaches that are used for outdoor OPV systems need to be modified because of the differences between the indoor and outdoor output spectra and incident light intensities[9]. Minimizing optical loss, suppressing leakage current, and providing optimum spectrum matching between the absorption spectral range of the photoactive layers and the output spectra of the indoor light source are crucial for the efficient indoor performance of OPVs10,11. Transparent conducting electrodes (TCEs) play a major role in indoor OPV systems, as most indoor performance requirements are functions of the properties of the TCE11
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
