Photoenhanced chemical vapor deposition of zinc phosphide

Abstract

Thin films of zinc, phosphorus, and zinc phosphide (Zn3P2) have been deposited by photodissociation of dimethylzinc (DMZ) and phosphine (PH3) on various substrates using a low-pressure mercury lamp as a light source. The substrate temperature was varied between room temperature and 250 °C. The deposition rates of the films were significantly affected by the UV light intensity, the density of gases, the PH3/DMZ molar ratio, and the substrate temperature. Zn3P2 microcrystallites were grown on Si(111) substrates at a temperature of 250 °C. Those crystallites were studied by using a scanning electron microscope and reflection high-energy electron diffraction. A very weak photoluminescence spectrum at 808 nm (1.53 eV) was observed at room temperature.

Showcasing the optical properties of monocrystalline zinc phosphide thin films as an earth-abundant photovoltaic absorber

“…A peak near the bandgap energy of zinc phosphide is always observed, albeit sometimes without being accompanied by a second peak at lower energy. 6,37,38 We have determined the nature of the transitions involved in the recombination processes for Zn 3 P 2 by investigating the excitation intensity dependence of the PL spectra. Models of the different recombination processes in semiconductors indicate that when the incident excitation power (P) is varied over a range of at least two orders of magnitude, the relationship between the intensity of a single PL peak (I) is related to it by a power law of the form: I B P k , where k is a coefficient depending on the nature of the transition.…”

Tailoring of Interfaces for the Photoelectrochemical Conversion of Solar Energy

“…The stability of these compounds has been attributed to the thermalization of photoexcited charge carriers to band edges that exhibit rather pure metal d -band character [63] . Therefore, the bonding between the metal and the chalcogenide is not affected and as a result these materials show surprising stability as photoelectrodes [64,65] . The electrodes mostly used, however, are compounds such as MoS 2 , MoSe 2 , and WSe 2 [77,78] .…”

Photoelectrochemical characterization of annealed cadmium selenide photoelectrode using sulphide–polysulphide electrolyte

“…A variety of binary semiconductors, especially from the II and VI groups of the periodic table, have been extensively studied due to their potential use in photoconductive solar cells. Cadmium selenide is one of the members of the II and VI families that has a suitable band gap to match the maximum of solar spectrum and also has high photosensitivity [4][5][6][7]. Photoelectrochemical cells with active semiconductor electrolyte junction are considered to be efficient solar energy harvestors, and intensive research is going on to use such systems for production of energy [8][9][10].…”