Journal of Physical Chemistry, Vol.99, No.41, 15262-15268, 1995
An Optically Detected Magnetic-Resonance Study of Laser-Ablation Grown Pbi2 Epitaxial-Films
Epitaxial films of PbI2 were grown by the laser ablation technique. The correlation between certain emission processes and lattice imperfections was examined, utilizing optically detected magnetic resonance (ODMR) spectroscopy. The present work focuses on the characterization of the nonexcitonic green and red emission bands. The results suggested that these emission processes are associated with a common donor state. Moreover, this donor state is participating also in nonradiative donor-acceptor recombination process. The quenching in luminescence intensity, pronounced in the ODMR measurement, indicates that the experiment detected actually the nonradiative recombination. Thus, the ODMR measurements identified a hole trapped at an isotropic nonradiative acceptor site with g(h) approximate to 2.05, that corresponds to the lead vacancy defect, [V-](Pb+2) . The photogenerated electron is trapped in an anisotropic radiative donor site with g(ell) approximate to 2.34 and g(e.l.) approximate to 1.73,associated with the iodine vacancy, [V-0](iodine).