The inverse temperature (T)-dependent methods yield single crystals of methylammonium lead halide perovskite with strained lattices. In contrast, the antisolvent diffusion method (antisolvent-vapor crystallization (AVC)) produces unstrained MAPbBr(3)crystals with more uniform growth features and lower density of defects.
The powder X-ray diffraction (XRD) measurements confirm the cubic and the tetragonal structure of the MAPbBr(3)and the MAPbI(3)samples, respectively. The XRD pole figure measurements (MAPbBr(3)) reveal a roughly parallel dominant (100) lattice plane to the sample surface.
An optimal crystal growth combines growth of a seed on an oriented substrate by the AVC method followed by either the AVC or a T-dependent method. The estimated resistivity rho and the density of trap staten(trap)values for the MAPbI(3)samples are 10(7)omega cm and 10(10)cm(-3), respectively.
The X-ray detection test reveals promising electrical properties of the MAPbI(3)material. Results from the Hall measurements in van der Pauw geometry for the MAPbBr(3)samples agree with those in the literature: the charge-carrier concentration of 10(9)-10(10)cm(-3)and the mobility of 7-289 cm(2) V(-1 )s(-1),n(trap)of 10(9)-10(10)cm(-3), and rho of 10(7)-10(8)omega cm.
These electrical parameters indicate that the MAPbBr(3)samples satisfy requirements for radiation sensors.