Activation of infrared emission in (iodine, nickel) Co-Doped CdS nanobelts for solar cells and optoelectronic applications

Abstract

Achieving tunable emission in semiconductors over a wide-spectral range has always remained a challenge for its potential applications. For this purpose, transition metals (TMs) have been widely doped into II-VI semiconductors, however, least efforts have been made on adding non-metals. Here, we co-doped non-metal and TM, i.e. iodine + nickel (I + Ni) into CdS 1D nanostructures and explored optical properties for the first time. FESEM shows that among CdS: (F + Ni, Cl + Ni, Br + Ni, I + Ni), I + Ni-doped CdS nanobelts (NBs) were thinner and have high crystallinity confirmed by XRD and Raman spectroscopy. Successful incorporation of iodine into CdS NBs was confirmed by EDX. Low temperature (80 K) photoluminescence (PL) of I + Ni doped CdS shows multiple emission centred at 525, 583, 758, and 916 nm, respectively. The first emission corresponds to exciton magnetic polaron (EMP) and the next two emissions correspond to d-d transition (3A2g → 1Eg) and (3T1P → 3T1F) of Ni ions, respectively. The last emission (916 nm) originated only in the I + Ni co-doped CdS NB which may correspond to the iodine incorporated into belts. According to the best knowledge, iodine related emission was detected for the first time. This work will promote their future applications in solar cells and optoelectronic devices.