▎ 摘　　要

Reduced graphene oxide incorporated potassium-doped zinc oxide (KZO:rGO) composite thin films were synthesized on glass substrates by spin coating technique. X-ray diffraction studies showed that lattice parameters of the hexagonal wurtzite structured potassium doped zinc oxide (KZO) thin films were decreased by the addition of reduced graphene oxide (rGO). The crystallinity of the peaks of composite thin films was slightly increased with rGO concentration owing to the increased amount of sp2 carbon domains in rGO. The energy band gap of the composite films was decreased with increasing rGO concentration is mainly due to the increased band tail states in KZO thin film. The absorptive nonlinearity and optical limiting properties of the KZO:rGO films were studied using Q-switched Nd:YAG laser at 532 nm. The induced absorption behavior of composite films was mainly attributed to the two photon absorption along with free carrier absorption. The KZO:rGO (3%) thin film exhibits lower optical limiting threshold value (61 MW/cm(2)) as compared with KZO. The strong nonlinear absorption of sp2 domains in rGO attributes to the optical limiting property of the composite material. Hence it is an excellent optical limiter which finds promising applications as a protecting material for sensitive photonic devices in the field of optoelectronics.