Spinel Co₃O₄ nanomaterials for efficient and stable large area carbon-based printed perovskite solar cells

Abstract

Carbon based perovskite solar cells (PSCs) are fabricated through easily scalable screen printing techniques, using abundant and cheap carbon to replace the hole transport material (HTM) and the gold electrode further reduces costs, and carbon acts as a moisture repellent that helps in maintaining the stability of the underlying perovskite active layer. An inorganic interlayer of spinel cobaltite oxides (CoO) can greatly enhance the carbon based PSC performance by suppressing charge recombination and extracting holes efficiently. The main focus of this research work is to investigate the effectiveness of CoO spinel oxide as the hole transporting interlayer for carbon based perovskite solar cells (PSCs). In these types of PSCs, the power conversion efficiency (PCE) is restricted by the charge carrier transport and recombination processes at the carbon-perovskite interface. The spinel CoO nanoparticles are synthesized using the chemical precipitation method, and characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy. A screen printed thin layer of p-type inorganic spinel CoO in carbon PSCs provides a better-energy level matching, superior efficiency, and stability. Compared to standard carbon PSCs (PCE of 11.25%) an improved PCE of 13.27% with long-term stability, up to 2500 hours under ambient conditions, is achieved. Finally, the fabrication of a monolithic perovskite module is demonstrated, having an active area of 70 cm and showing a power conversion efficiency of >11% with virtually no hysteresis. This indicates that CoO is a promising interlayer for efficient and stable large area carbon PSCs.

Promoting the Hole Extraction with Co3O4 Nanomaterials for Efficient Carbon‐Based CsPbI2Br Perovskite Solar Cells

“…For the CsPbI 2 Br/C film, the PL intensity significantly quenches due to the charge transfer from CsPbI 2 Br to carbon electrode. Those quenching effect is further enhanced in the CsPbI 2 Br/Co 3 O 4 /C film, indicating the significantly enhanced charge extraction in this film . This can be further confirmed by time‐resolved PL (TRPL) measurement.…”

“…The diffraction peaks at 14.6 and 29.5° are, respectively ascribed to the (100) and (200) crystal planes of CsPbI 2 Br, implying the good crystallinity of CsPbI 2 Br . The characteristic peaks at 31.31 and 36.81° attributed to the (220) and (311) crystal planes of Co 3 O 4 (ICDD: 01‐080‐1545) can be clearly seen in Figure d and almost no shift of the diffraction peaks in the CsPbI 2 Br/Co 3 O 4 film is observed . The result demonstrates the existence of Co 3 O 4 on the CsPbI 2 Br film and the crystal structure of CsPbI 2 Br does not change after the spin‐coating of Co 3 O 4 layer.…”

One‐Step Controllable Synthesis of Mesoporous MgCo2O4 Nanosheet Arrays with Ethanol on Nickel Foam as an Advanced Electrode Material for High‐Performance Supercapacitors

“…This may be caused by the different morphologies of MCN‐1and MCN‐2. Figure b shows the three‐dimensional atomic structure of the spinel MgCo 2 O 4 unit cell, which is a normal cubic spinel structure with Mg ions occupying tetrahedral sites, Co ions occupying octahedral sites, and isostructural with Co 3 O 4 structures …”

Rapid Thermal Treatment of Reactive Sputtering Grown Nanocrystalline Co3 O4 for Enhanced All-Oxide Photovoltaics

“…The results certainly indicate that Co 3 O 4 all‐oxide performances are limited due to the low FF and photocurrent. Interestingly, cobalt oxide interlayer enhances the performance of perovskite and polymer solar cells due to the efficient hole‐transporting characteristics . Despite progress, the control of carrier concentration and mobility in Co 3 O 4 and the implications for Co 3 O 4 photovoltaics have not been examined to our knowledge.…”