Background: Ternary semiconducting compounds having a stoichiometry of 1:1:1 and an element combination selected from the set of I-II-V I-III-IV II-II-IV and I-I-VI; or having a stoichiometry of 3:1:2 and an element combination selected from the set of I-III-V; or having a stoichiometry of 2:1:1 and an element combination selected from the set of I-II-IV. For example Li3AlN2 (band gap 4.4eV) and LiMgN (band gap 3.2eV) are particularly suitable for wide band gap applications such as LED in the blue to ultraviolet spectrum and transparent electrodes. NaZnAs CaCuN CaCuP NaZnSb CuZnP NaZnP and NaZnN having a direct band gap in the range of 0.8eV to 2.0eV are suitable for photovoltaic applications. The elements in these materials can be partially replaced by elements of the same group in the one-by-one manner to maintain their insulating nature. For example LiMgN can be tuned to be LiMg1-xZnxN. By tuning the materials their band gap can be continuously changed to cover a broad light spectrum. Technology Description: Stanford researchers have developed new ternary semiconducting compounds for optical device applications as potential replacements for conventional materials like GaN CIGS and ITO. These ternary compounds can be used to form the radiation absorption layer of a photovoltaic cell the light emitting material of a light emitting device the gain medium of a laser diode the light absorbing layer of the photodetection device the absorption medium of a modulator a transparent electrode or a window layer. Most of these materials are theoretically predicated while some such as Li3AlN2 have already been synthesized. Further development towards producing prototype devices is in progress. Ternary semiconductor to replace binary compounds with similar band gaps can be formed by maintaining 8 or 18 total valence electrons. Applications: 1) Radiation absorption layer of a photovoltaic cell 2) Light emitting material of a light emitting device 3) Gain medium of a laser diode 4) Light absorbing layer of the photodetection device 5) Absorption medium of a modulator 6) Transparent electrode or a window layer
The ternary semiconducting compounds of the present invention provides advantages over conventional semiconductor materials in that the ternary semiconducting compounds are made from materials that are abundant in nature resulting in lower material cost. The ternary semiconducting compounds of the present invention may also be easier to manufacture due to their crystal structures as compared to other materials of similar band gap. For example the stable phase for GaN and ZnO is wurtzite lattice (hexagonal unit cell) while the stable phase of Li3AlN2 and LiMgN is zinc-blende lattice (cubic unit cell) allowing high quality thin films to be grown on an inexpensive silicon substrate of diamond lattice (also cubic) with a small lattice mismatch.