Highly In-Plane Polarization-Sensitive Photodetection in CsPbBr3 Single Crystal

The fully inorganic perovskite lead cesium bromide single crystal (CsPbBr₃ SC) is considered as an excellent candidate semiconductor for photodetectors because of its superior humidity resistance, thermal stability, and light stability compared with organic-inorganic hybrid perovskites as well as its photoelectric properties such as large light absorption coefficient and ultralong carrier migration distance. In this Letter, we utilize the inverse temperature solubility of CsPbBr₃ in ternary solvents to grow large-sized CsPbBr₃ SCs. By the use of the (101) plane, CsPbBr₃ SC-based photodetectors are fabricated, which exhibit excellent polarized light response characteristics. The photocurrent relies on the polarization angle in a sinusoidal fashion and shows strong anisotropic optoelectronic properties. The photodetection performance perpendicular to the y axis is significantly higher than that parallel to the y axis, and the dichroic ratio under 405 nm illumination at a bias voltage of 1 V reaches 2.65. The experimental results are consistent with the results of first-principles calculations.