Preparation And Photoelectronic Properties Of Cs₂AgBiBr₆ Crystals

Sensitive X-ray detector finds essential applications for medical diagnostics,security screening,and industrial product inspection.Recently,3D Cs₂AgBiBr₆ and 0D Cs₃Bi₂X₉ singles and thin films are considered to be a promising candidate for X-ray detection due to its remarkable stability,nontoxicity,high sensitivity and low detection limit.In this paper,based on the stoichiometric ratio,the effects of different additives on crystal size and properties were studied by adding different solutes and solvents.The detail are as folllows:(1)Growth and properties of centimeter-sized lead free all inorganic perovskite Cs₂AgBiBr₆crystal by additive CH₃COONa.Different additives agents were added into the Cs₂AgBiBr₆precursor solution.In addition,the concentration of additives agents were optimized.We have found that Cs₂AgBiBr₆ with the maximum size of 13 mm have been successfully grown by slowly cooling the solution with additive 30%CH₃COONa.The Powder X-ray diffraction of Cs₂AgBiBr₆ single crystal revealed that the as-grown crystal had a good single crystallinity.In our work,the dark current-voltage curves before and after annealing were tested,the resistivity before and after annealed are 8.51×10⁹?·cm and 1.16×10¹⁰?·cm,the results illustrated annealed is friendly for resistivity was increased.The on-off ratio is 1.38.(2)Growth and properties of centimeter Cs₂AgBiBr₆ lead-free inorganic perovskite crystal by Anti-solvent method.The Cs₂AgBiBr₆ single crystal with maximum dimensions of 10 mm was synthesized by controlled cooling method in solution with toluene.X-ray diffraction measurement of powder and plane demonstrates that the crystal belongs to cubic structure.Therefore,toluene is a good anti-solvent for grown Cs₂AgBiBr₆ double perovskite.Further,photodetector behaviors of Cs₂AgBiBr₆ based on Ag/Au electrodes illustrate between Ag and Cs₂AgBiBr₆ enjoy to good Ohimc contact behavious.The resistivity is 3.29×10¹⁰?·cm and on-off ratio is 1.38.(3)Growth and properties of centimeter-sized lead free all inorganic perovskite Cs₃Bi₂X₉(X=Br,Cl)crystal.In this paper,Cs₃Bi₂Br₉ single crystal with the size of 10 mm×10 mm×5 mm and Cs₃Bi₂Cl₉single crystal with the maximum size of 10 mm were grown via slowly cooling solution method.The crystal data and structure refinement for Cs₃Bi₂Cl₉ and the PXRD of Cs₃Bi₂Br₉ crystal illustration that the unit cell dimensions of two crystals.The DTA and TG curves shows that the two crystals have high thermal stability.Further,current-voltage cueves shows that the resistivity of Cs₃Bi₂Cl₉ and Cs₃Bi₂Br₉ crystals are 1.01×10¹²?·cm and 1.23×10¹¹?·cm,it proved that these two crystals are suitable for X-ray detection field.