Energy band structures of Cd₃P₂ and Zn₃P₂

Abstract

A pseudopotential energy band calculation is carried out for a hypothetical crystal which corresponds to Cd,P, and Zn,P,. From these results, the conduction band effective masses as well as the interband transition assignments associated with the optical reflectivity peaks are deduced. The temperature dependence of the energy gap for these materials is estimated and dE,/dT is shown to be negative.Mit der Pseudopotential-Methode wird eine Energiebandberechnung fur einen hypothetischen Kristall, der C$P, und Zn,P, entspricht, durchgefuhrt. Mit diesen Ergebnissen werden die effektiven Massen des Leitungsbandes sowie die Zuordnungen der Interbandiibergltnge zu den Maxima des optischen Reflexionsvermogens hergeleitet. Die Temperaturabhangigkeit der Energielucke wird fur diese Stoffe abgeschltzt und gezeigt, daS dE,,dT negativ ist.

Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2

“…[7][8][9][10][11][12] Some absorption measurements have led to assignments of the fundamental band gap as direct, [7][8][9] whereas others have concluded that the fundamental gap is indirect. [10][11][12] Computational methods using empirical pseudopotentials have also yielded both direct [13][14][15] and indirect 13,16 transitions at the fundamental band gap, depending whether the crystal structure is modeled as a cubic antifluorite or as a tetragonal structure. A fundamental indirect gap is supported by investigations of the spectral response properties of Mg Schottky diodes 17 and of aqueous photoelectrochemical cells, 5 which have produced estimates of an indirect gap at 1.37 and 1.43 eV, respectively.…”

“…The feature in the n͑͒, k͑͒ data at 2.5 eV indicates a high density of states, presumably associated with a higher lying band, perhaps the at ⌫ 25 point. 14 This n͑͒, k͑͒ data set, that extends through the entire visible spectrum, is expected to be valuable for future optoelectronic device modeling of Zn 3 P 2 solar cells.…”

Energy Band Structure of Zn3P2-Type Semiconductors: Analysis of the Crystal Structure Simplifications and Energy Band Calculations

“…The first attempt to calculate the band structure of phosphide-type compounds (Zn 3 P 2 , Cd 3 P 2 ) was done by Lin-Chung [26]. The crystal structure has been simplified by two assumptions: 1. the lattice constants a and c of the real symmetry obey the relation a ¼ c= ffiffi ffi 2 p ; 2. the unit cell is formed simply by filling the metal vacant sites by fictitious atoms.…”

“…The antifluorite approximation is most widely used for the calculations of the band structure of II-V compounds [26][27][28]. Another approximation is the so called zincblende approximation [29].…”

“…In [30] the authors tried to improve the agreement between theory and experiment for the Lin-Chung [26] model. In this work the value of spin-orbit splitting in the antifluorite approximation, i.e.…”