Premium
Ammonothermal Synthesis, Optical Properties, and DFT Calculations of Mg 2 PN 3 and Zn 2 PN 3
Author(s) -
Mallmann Mathias,
Maak Christian,
Niklaus Robin,
Schnick Wolfgang
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201803293
Subject(s) - wurtzite crystal structure , orthorhombic crystal system , band gap , materials science , crystallite , nitride , direct and indirect band gaps , ternary operation , crystallography , analytical chemistry (journal) , crystallization , crystal structure , zinc , chemistry , nanotechnology , optoelectronics , metallurgy , organic chemistry , layer (electronics) , computer science , programming language , chromatography
The phosphorus nitrides, Mg 2 PN 3 and Zn 2 PN 3 , are wide band gap semiconductor materials with potential for application in (opto)electronics or photovoltaics. For the first time, both compounds were synthesized ammonothermally in custom‐built high‐temperature, high‐pressure autoclaves starting from P 3 N 5 and the corresponding metals (Mg or Zn). Alkali amides (NaNH 2 , KNH 2 ) were employed as ammonobasic mineralizers to increase solubility of the starting materials in supercritical ammonia through formation of reactive intermediates. Single crystals of Mg 2 PN 3 , with length up to 30 μm, were synthesized at 1070 K and 140 MPa. Zn 2 PN 3 already decomposes at these conditions and was obtained as submicron‐sized crystallites at 800 K and 200 MPa. Both compounds crystallize in a wurtzite‐type superstructure in orthorhombic space group Cmc 2 1 , which was confirmed by powder X‐ray diffraction. In addition, single‐crystal X‐ray diffraction measurements of Mg 2 PN 3 were carried out for the first time. To our knowledge, this is the first single‐crystal X‐ray study of ternary nitrides synthesized by the ammonothermal method. The band gaps of both nitrides were estimated to be 5.0 eV for Mg 2 PN 3 and 3.7 eV for Zn 2 PN 3 by diffuse reflectance spectroscopy. DFT calculations were carried out to verify the experimental values. Furthermore, a dissolution experiment was conducted to obtain insights into the crystallization behavior of Mg 2 PN 3 .