Domain Engineering of PMN‐PT for Advancing Electro‐Optic and Optoelectronic Device Performance

Abstract Relaxor ferroelectric Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 (PMN ‐ PT) has attracted enormous attention in the field of ultrasonic imaging and non‐destructive evaluation, due to its distinguished electromechanical coupling coefficient. However, the existence of complex phase transition and disordered polarization domains restricts its optical transparency, greatly limiting the emerging optoelectronic applications. In this work, a process‐friendly direct‐current poling is utilized to achieve orientational manipulation of the ferroelectric domains, demonstrating ≈68.5% transmission among visible to the near‐infrared band. Comparative investigations indicate that the electro‐optic coefficient of the specimen can be improved to 588 pm V −1 at 1 MHz at room temperature after poling treatment, even ≈29 times higher than that of conventional lithium niobate bulks. Besides, robust pyroelectric photoresponse can be observed in the case of direct current (DC)‐poled PMN‐PT, covering the whole visible range. In addition, enhanced conversion efficiency from fundamental frequency wave to second harmonic generation wave is obtained. This work paves the way for PMN‐PT crystals toward optoelectronic applications based on a ferroelectric domain engineering approach.