Tantalum Oxide as an Efficient Alternative Electron Transporting Layer for Perovskite Solar Cells

Abstract

Electron transporting layers facilitating electron extraction and suppressing hole recombination at the cathode are crucial components in any thin-film solar cell geometry, including that of metal–halide perovskite solar cells. Amorphous tantalum oxide (Ta2O5) deposited by spin coating was explored as an electron transport material for perovskite solar cells, achieving power conversion efficiency (PCE) up to ~14%. Ultraviolet photoelectron spectroscopy (UPS) measurements revealed that the extraction of photogenerated electrons is facilitated due to proper alignment of bandgap energies. Steady-state photoluminescence spectroscopy (PL) verified efficient charge transport from perovskite absorber film to thin Ta2O5 layer. Our findings suggest that tantalum oxide as an n-type semiconductor with a calculated carrier density of ~7 × 1018/cm3 in amorphous Ta2O5 films, is a potentially competitive candidate for an electron transport material in perovskite solar cells.

Tantalum Suboxide Films with Tunable Composition and Electrical Resistivity Deposited by Reactive Magnetron Sputtering

“…A recent report for amorphous Ta 2 O 5 found a carrier density of ∼7 ×10 18 cm −3 at room temperature [34], which is consistent with the trend observed here. The carrier mobility, by contrast, is relatively low and does not display a systematic trend with the O content or temperature (Figure 5e), consistent with a highly disordered (amorphous) state of these films.…”

Expounded Photoelectric and Electrochemical Profiling of LRE3+:β‐Ta2O5 (Ln3+ = Ce3+, Pr3+, Nd3+) for High Performance in Energy Systems

“…The comparison of the fabricated solar cell with the CsPbI 2 Br light and LRE 3+ ‐doped Ta 2 O 5 ETL with the relevant research demonstrates the impressive performance. For instance, in a recent investigation, Deo et al, [ 41 ] Ta 2 O 5 has been used as an ETL and an alternative to the conventionally used ETLs. The developed PSC device in this case succeeded in achieving an efficiency of ≈14%, which is quite close to the PCE obtained in the current research.…”

Hydrophobic and Transparent Tantalum Pentoxide-Based Coatings for Photovoltaic (PV) Solar Panels

“…Solar photovoltaic technology has developed rapidly in the last ten years due to its environmental friendliness and sustainability [1][2][3][4][5][6][7][8]. As global energy demand increases, the conversion of solar energy into electrical energy emerges as an alternative.…”

“…The efficiency reported [4] for Si-based solar cells is between 10.2% in the case of Si (amorphous cell) and 26.7% for Si (multi-crystalline cells). Another type of PV panel is based on the perovskite solar cells [1][2][3]. The conversion efficiency of perovskite solar cells increased from 3.8% in 2009 to 28.75% in 2023 [5].…”

“…The band gap increases with ZnO doping and with the temperature of treatment. Deo [2] studied amorphous tantalum oxide (Ta 2 O 5 ) deposited by spin coating as an electron transport material for perovskite solar cells, achieving power conversion efficiency up to ~14%. Amorphous Ta 2 O 5 films can be the electron transporters in perovskite cells due to tantalum oxide as an n-type semiconductor with a calculated carrier density of ~7 × 10 18 /cm 3 [2].…”