Nitrogen states in Ga(As,P) and the long-range, short-range model: A systematic study

Abstract

The long-range, short-range model of the nitrogen isoelectronic impurity in Ga(As, P) is discussed in terms of the results of recent photoluminescence and lifetime measurements. The predictions of the theory are shown to depend sensitively upon the strength of the coupling among the states produced separately by the long-and short-range parts of the potential: The strength of the coupling reflects the specific model of potential used in all cases treated. Strong coupling yields theoretical energies whose general composition dependence mirrors the features of the data. The effect of consideration of the L-conduction-band minima is smaller. Determination of potential parameters from experimental energies indicates a range-20-25 A. Luminescence calculations require an accurate treatment of the continuum contribution. Predictions of the theory are in good agreement with available data. Inclusion of L indicates the existence of an excited nitrogen state in GaP. No internal inconsistencies in the theory are found.

Bandgap Tuning of High Mobility Magnetron Sputtered Copper (I) Oxide Thin Films for Perovskite Solar Cell Applications

“…cupric oxide) [2,3] films mainly due to the oxidization process of copper films. The optical properties vary for both Cu2O and CuO as reported previously [4][5][6][7] mainly due to the growth process resulting in rich or poor oxygen bonding. It has been reported that Cu2O confirms an optical bandgap between 2.10 and 2.60 eV [4,5], whereas for CuO, it is between 1.3 and 2.1 eV [6,7].…”

An extended Derjaguin-Landau-Verwey-Overbeek theory approach to determining the surface energy of copper oxide thin films prepared by reactive magnetron sputtering

“…We obtained direct optical bandgap values of 2.4 eV for the film deposited at 200 W power, 2.2 eV for the 600 W film, and 2.05 eV for the film prepared at 800 W power. A range of direct optical bandgap energies has also been reported for Cu 2 O [19,20,21] and CuO [21] semiconductor films in the literature depending on the method of fabrication and stoichiometry. The reported direct optical bandgap energy values for Cu 2 O range from 2.10 to 2.6 eV, [19,20,21] while values of 1.3 to 2.1 eV [21] have been reported for CuO.…”

“…A range of direct optical bandgap energies has also been reported for Cu 2 O [19,20,21] and CuO [21] semiconductor films in the literature depending on the method of fabrication and stoichiometry. The reported direct optical bandgap energy values for Cu 2 O range from 2.10 to 2.6 eV, [19,20,21] while values of 1.3 to 2.1 eV [21] have been reported for CuO. The Cu 2 O oxide films are reported to have high transparency, with a slightly yellowish appearance, and absorb usually at wavelengths below 600 nm, while CuO absorbs strongly throughout the visible spectrum and is black in appearance.…”

“…On the basis of these reported direct optical bandgaps in copper oxide films in the literature [19,20,21] and XPS investigation, we infer that the copper oxide films prepared at 200 W and 4 sccm oxygen flow rate are Cu 2 O-rich films, while the films prepared at 800 W power and 4 sccm oxygen flow rate are CuO-rich films. The film prepared at 600 W power and 4 sccm oxygen flow rate is a mixture of Cu 2 O and CuO phases based on XPS measurements [22] and an observed low optical transmission in these films.…”

Influence of Local Environment on Bound Excitons and Bound Excitonic Molecules in III‐V Alloys. I. Theory and Numerical Results for GaAs1−xPx:N

“…Notice that the difference potential in (25) is the same as in Pitoch in (9). Therefore, it will be possible to calculate the energy of a Bloch electron (a = e) or hole (a = h) a t concentrations x + 6x in the frame of perturbation theory, by…”