Ag2[TeO2(OH)4]: a nonlinear optical tellurate with balanced comprehensive performance

Abstract

Nonlinear optical (NLO) crystals are crucial components in all-solid-state lasers because they expand the wavelengths of existing laser sources through laser frequency conversion. In this work, Ag₂[TeO₂(OH)₄] was identified in tellurates using the first-principles high-throughput screening pipeline for NLO materials (FHSP-NLO). The material was successfully produced via mild aqueous solution synthesis conditions, and a single crystal of 8 × 4 × 4 mm³ in size was obtained. Ag₂[TeO₂(OH)₄] is one of the few materials that contains the [TeO₂(OH)₄]²⁻ anionic group and belongs to the non-centrosymmetric (NCS) space group. Ag₂[TeO₂(OH)₄] exhibited balanced comprehensive performances, including a large second harmonic generation (SHG) response of about 0.84 × AgGaS₂ (AGS), moderate band gap (2.73 eV) and large birefringence (0.106@1064 nm). First-principles studies revealed that the dominant units that contribute to the crystal's linear and nonlinear optical properties are Ag atoms and TeO₂(OH)₄ groups.