Low-Temperature Solution-Processed SnO₂ Nanoparticles as a Cathode Buffer Layer for Inverted Organic Solar Cells

Abstract

SnO recently has attracted particular attention as a powerful buffer layer for organic optoelectronic devices due to its outstanding properties such as high electron mobility, suitable band alignment, and high optical transparency. Here, we report on facile low-temperature solution-processed SnO nanoparticles (NPs) in applications for a cathode buffer layer (CBL) of inverted organic solar cells (iOSCs). The conduction band energy of SnO NPs estimated by ultraviolet photoelectron spectroscopy was 4.01 eV, a salient feature that is necessary for an appropriate CBL. Using SnO NPs as CBL derived from a 0.1 M precursor concentration, P3HT:PCBM-based iOSCs showed the best power conversion efficiency (PCE) of 2.9%. The iOSC devices using SnO NPs as CBL revealed excellent long-term device stabilities, and the PCE was retained at ∼95% of its initial value after 10 weeks in ambient air. These solution-processed SnO NPs are considered to be suitable for the low-cost, high throughput roll-to-roll process on a flexible substrate for optoelectronic devices.

Effect of Film Thickness on Photoelectrochemical Performance of SnO2 Prepared via AACVD

“…Generally, all samples exhibited light transmittance of over 70% with respect to air for wavelength above 390 nm. The light transmittance of SnO 2 ‐coated FTO substrate decreases as the thickness of SnO 2 layer increases which agrees well with the previously observed transmittance spectra . It can also be seen that the transmittance spectra of bare FTO and SnO 2 ‐coated FTO indicated fluctuating pattern as a result of low reflectivity and interference effect of scattered light within the FTO and SnO 2 layers …”

An Analytical Solution to Lumped Parameter Equivalent Circuit Model of Organic Solar Cells

“…Compared with the conventional silicon-based solar cells, organic solar cells (OSCs) [1,2], as promising candidates for next generation solar cells [3][4][5][6], show many advantages in intensive researches, such as low temperature preparation [2], flexibility [7], and so on. However, as the important physical phenomena, S-shaped kink exhibits in I-V characteristics of OSCs, especially for the polymer OSCs [7][8][9].…”

An Improved Organic Solar Cell Lumped-Parameter Equivalent Circuit Model

“…Over the last two decades, organic photovoltaic devices [1] have attracted much attention and undergone intensive research due to their many potential advantages over conventional silicon-based solar cells, such as low-cost printing [2] and fabrication on flexible substrate [3]. However, the power conversion efficiency (PCE) of organic solar cells (OSCs) still cannot approach that of conventional silicon-based solar cells because the S-shaped kinks that are tested according to the I-V characteristics of polymer OSCs [4,5] can damage the PCE.…”