Microwave modulated and thermal modulated photoluminescence studies of 2H-lead iodide

Abstract

Lead iodide, Pb12, is a layered semiconductor. The luminescence processes, of 2H-PbI2 single crystals, have been examined utilizing microwave modulated photoluminescence (MMPL) and thermal modulated photoluminescence (TMPL) spectroscopies. In the MMPL experiment, the microwaveelectric field induces a thermal heating of free carriers. The hot carriers effect on luminescence processes is discussed. On the basis of the experimental evidence, we suggest that the hot carriers influence the luminescence processes of excitons by reducing their cross section of formation. The TMPL experiments showed that thermal modulation has created a bolometric effect followed by equilibrium redistribution of carriers among the emitting states.

Study of the influence of the rare-earth elements on the properties of lead iodide

“…Low-temperature PL spectra [15,16] of typical PbI 2 crystals prepared by direct synthesis and/or by the ''single growth'' are shown in Figs. 6-8.…”

Synthesis of PbI2 with admixture of rare earth elements: Electrical and optical properties

“…Samples prepared with the addition of Ce, Yb, Er or without RE are characterized by spectra very similar to the spectrum labeled as (a). Exciton recombination bands at 4980 nm (2.488 eV) as well as shallow donor level at 5097 nm (2.43 eV) with 5-8 meV LO phonon replicas [5] could be observed on samples prepared with holmium admixture. Yet, PL spectra measured on samples prepared with the admixture of terbium, ytterbium, cerium and erbium do not show neither the fine structure of the excitonic band nor the LO phonon replicas of the shallow donor defect level.…”

Modulation frequency dependence of continuous-wave optically/electrically detected magnetic resonance

“…sity 6,7,13,18,41,[48][49][50] (or an injection current for EDMR 30,41,51 ), temperature 6,10,30,41 , and MW power (equivalently B 1 field strength) 6,7,12,[17][18][19][20]26,40,43,46,[52][53][54][55] .…”

“…The time scales on which these processes occur depend on various experimental parameters, such as excitation den- sity 6,7,13,18,41,[48][49][50] (or an injection current for EDMR 30,41,51 ), temperature 6,10,30,41 , and MW power (equivalently B 1 field strength) 6,7,12,[17][18][19][20]26,40,43,46,[52][53][54][55] .…”

“…Qualitative reports of modulation frequency dependencies can be found in the early ODMR and EDMR literature 5,10,14 which were sometimes used to identify the overlap of separate spin-dependent signals 7 . Even so, very little systematic research into modulation frequency effects was undertaken before the late 1990's, when research into this question became more common 19,20,26,31,[37][38][39]46,[49][50][51] .…”