Ionization energy of the phosphorus donor in 3C–SiC from the donor-acceptor pair emission

Donor-acceptor pair luminescence of P–Al and N–Al pairs in 3C–SiC is analyzed. The structures in the spectra corresponding to recombination of pairs at intermediate distances are fitted with theoretical spectra of type I (P–Al pairs) and type II (N–Al pairs). It is shown that in the regions chosen for fitting the line positions obey the equation ℏω(R)=EG−ED−EA+e2/eR, where ℏω(R) is the energy of the photon emitted by recombination of a pair at a distance R, e is the electron charge, e is the static dielectric constant, and EG, ED, and EA are the electronic band gap and the donor and acceptor ionization energies, respectively. The fits yield the values EG−ED−EA for the N–Al (2094 meV) and P–Al (2100.1 meV) cases. Using the known value of the nitrogen ionization energy, 54.2 meV, phosphorus ionization energy of 48.1 meV is obtained. Identification of the sharp lines corresponding to recombination of close pairs in the P–Al spectrum is suggested.