Indirect bandgap, optoelectronic properties, and photoelectrochemical characteristics of high-purity Ta₃N₅ photoelectrodes

Abstract

The (opto)electronic properties of Ta3N5 photoelectrodes are often dominated by defects, but precise control of these defects provides new insight into the electronic structure, photocarrier transport, and photoelectrochemical function.

Characterizing Density and Spatial Distribution of Trap States in Ta3N5 Thin Films for Rational Defect Passivation

“…The core lines of Ta 4f 7/2 and Ta 4f 5/2 can be observed at 25.25 and 27.16 eV, respectively; the position and splitting of 1.9 eV is consistent with those measured for Ta 3 N 5 films reported in the literature. − The broader doublet with peaks at 25.94 and 27.85 eV can be ascribed to a tantalum oxynitride species (TaO x N y ) with y > x . The N 1s peak associated with Ta 3 N 5 is observed at 396.72 eV and in agreement with those reported in the literature. , The broad peak observed at slightly higher binding energies around 403 eV has been attributed to the Ta 4p 3/2 of tantalum oxide and is again indicative of a mixed species at the surface. , Characterizing the O 1s spectrum measured and fit for the neat films, the peak corresponding to lattice-incorporated oxygen (TaO x N y ) is observed at 530.70 eV while those generally assigned to either −OH or adsorbed H 2 O at the surface of films are measured at 531.95 and 533.30 eV, respectively . This has been used to determine the surface of neat films have a composition of N/Ta = 1.42, O/Ta = 0.63, and (O+N)/Ta = 2.05, consistent with the well-reported formation of TaO x N y on the surface of Ta 3 N 5 materials and the surface-sensitive nature of XPS measurements. − , …”

“…7 The N 1s peak associated with Ta 3 N 5 is observed at 396.72 eV and in agreement with those reported in the literature. 29,31 The broad peak observed at slightly higher binding energies around 403 eV has been attributed to the Ta 4p 3/2 of tantalum oxide and is again indicative of a mixed species at the surface. 3,32 Characterizing the O 1s spectrum measured and fit for the neat films, the peak corresponding to lattice-incorporated oxygen (TaO x N y ) is observed at 530.70 eV while those generally assigned to either −OH or adsorbed H 2 O at the surface of films are measured at 531.95 and 533.30 eV, respectively.…”

First-Principles Studies of Strain-Adjustable Janus WSSe Monolayer/g-GeC Monolayer Heterojunctions: Implications for Photoelectric and Switching Devices

“…In addition, 2D materials have excellent optoelectronic properties, allowing them to show potential in optoelectronic devices. − The band gap tunability and the ability to absorb light over a wide wavelength range make them ideal substrates for photodetectors, light modulators, and light emitting devices. The fast response time, high sensitivity, and broad band properties of these devices in range from visible to infrared light make them promising for applications in communications, photonic computing, and sensing.…”

Crystal structure engineering of metal halide perovskites for photocatalytic organic synthesis

“…13 The emission peak of Cs 3 BiBr 6 shows a slight blue shift, which could be attributed to its indirect bandgap property. 22 Photoelectrochemical measurements were further performed to reveal the picture of charge separation and transfer. 23 Fig.…”

“…13 The emission peak of Cs 3 BiBr 6 shows a slight blue shift, which could be attributed to its indirect bandgap property. 22…”