Facile hydrothermally synthesized nanosheets-based Cu0.06-xNi0.03Sn0.03+xS0.12 flower for optoelectronic and dielectric applications

The present investigation reports the preparation of Cu_0.06-xNi_0.03Sn_0.03+xS_0.12 (CNTS) nanosheets (NS) by hydrothermal method and its dielectric and optical behavior. The as-prepared CNTS samples with different Sn content exhibit polycrystalline nature with primary stannite phase along with several secondary phases. The CNTS samples show nanoflower-like morphology consisting of self-assembled NS of an average thickness of 40–50 nm. The morphology remains invariant, but a variation in the band edge absorption and corresponding bandgap variation is observed for the increase in Sn content. The photoluminescence emission with 532 nm excitation of CNTS nanosheets shows the peaks in orange-red regions. The visible emission is primarily due to the presence of different defect states in the NS. From the frequency and temperature-dependent dielectric study, AC conductivity and the impedance spectroscopy-related parameters were evaluated. In the low-frequency region, the CNTS behaves like an unpolarized material, whereas in the high-frequency region, it facilitates the hopping of charge carriers due to the increased frequency range. The electrical conduction is due to the cumulative result of the hopping of charge carriers across the barrier potential and tunneling of polarons formed due to lattice distortion at high temperatures. The behavior of the complex impedance parameters validates the negative temperature coefficient of resistance and the decrease in bulk resistance with the increase in temperature. The tunable semiconducting properties, along with the excellent optical and dielectric behavior of the CNTS materials, promote its application in various cutting-edge optoelectronic and dielectric devices.