GROWTH AND CHARACTERIZATION OF N-DOPED ZNSXSE1-X (0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-0.3) BY MOLECULAR-BEAM EPITAXY

N-doped p-type ZnSxSe1-x (0 less than or equal to x < 0.3) films were grown by molecular beam epitaxy (MBE) using radio-frequency (RF) plasma. The net acceptor concentration N-a-N-d decreased monotonically with increasing S composition and N-a- N-d of 2.5 x 10(17) cm(-3) was achieved for the ZnSxSe1-x film with S composition of 0.29, which has a bandgap energy of 3.0 eV at 77 K. The relative intensity of the I-1 peak (acceptor bound exciton) to DAP (donor-acceptor pair) emission increased with increasing S composition and the DAP emission became dominant with increasing temperature. From the temperature dependence of photoluminescence (PL) measurements, the activation energies of the N acceptor in ZnSxSe1-x were estimated. The activation energy increased with increasing S composition and was comparable to that of ZnMgSSe.