Rationally Designed Cu-Ion Implantation-Improved 2D Perovskite BDAPbI₄ Photodetector

Abstract

Two-dimensional (2D) Dion−Jacobson (DJ) perovskites have recently drawn much attention owing to their superior charge transport and high environmental stability. We fabricated centimeter-sized BDAPbI 4 (BDA = NH 3 C 4 H 8 NH 3 2+ ) 2D perovskite single crystals with an optical band gap of 2.30 eV, as well as the corresponding photodetectors. Based on the density functional theory calculations, rational design of the ion implantation scheme was carried out to improve the performance of the BDAPbI 4 photodetector. The Cu ion is screened out to be the best element, which can introduce the additional sub-bands below the CBM of the pristine perovskite. The Cu 4s orbital dominates the CBM states, and the Cu 3d orbital dominates the VBM states. It exhibits high charge collection efficiency and improves light harvesting ability. The reduced band gap, enhanced density of states, and improved absorption coefficient indicate that Cu-ion implantation could significantly increase the charge carrier concentration and promote the charge dissociation and extraction across the band edge, which is beneficial to improve the performance of BDAPbI 4 -based photodetectors. In particular, the BDAPbI 4 photodetector modified by Cu-ion implantation exhibits improved photoresponse performance with the best responsivity of 0.66 mA W −1 under a high light intensity of 10.8 mW cm −2 at 40 V bias, which is about twice as that of the pristine BDAPbI 4 devices. This study provides a promising way to improve the performance of 2D perovskite single-crystal photodetectors by ion implantation.

Enhancement of CsPbBr3 Perovskite Single-Crystal Photodetector Performance via Zr Ion Implantation

“…The smaller the E g , the more suitable for PDs . These results indicate that more photogenerated carriers will be generated in the Zr ion implanted CsPbBr 3 single crystal than the pristine one under the same light intensity, and Zr ion implantation is a feasible way to improve the optical properties of CsPbBr 3 single crystals. The PL spectra of pristine and Zr ion implanted CsPbBr 3 single crystals are shown in Figure d.…”

“…The molecular dynamics (MD) is employed to simulate the structure of Zr ion implanted CsPbBr 3 in equilibrium state, and the result is shown in Figure S12. The kinetic energy of the implanted Zr ion oscillates in the initial stage and decreases to a smaller value (<0.5 eV) after about a 0.1 ps equilibrium run, and the result shows the structure is very stable . The calculated band gap of the Zr ion implanted CsPbBr 3 is 1.86 eV (Figure c).…”

“…The enhanced intensity of PL after implantation indicates an increase in the density of photogenerated carriers, resulting in improvement of photocurrent at higher light intensities. So the introduction of Zr ions promotes the production of more photogenerated carriers in the crystal, due to the Zr 4d orbitals promoting carrier transport as new carrier transport channels, which is conducive to improve the optoelectronic performance of the device . The Zr ion implantation can enhance the device performance under different light intensities and bias voltages, giving rise to a higher photocurrent for the Zr ion implanted device compared to the pristine device.…”

“…It is worth mentioning that the Zr ion doping can improve the stability, carrier lifetime, and photoluminescence quantum yield (PLQY) of CsPbBr 3 quantum dots . The traditional chemical method for metal ion doping mentioned above has difficulty achieving uniform doping, especially in high concentration metal ion doping of single crystals. ,− As a physical doping method, ion implantation can control the doping elements in the form of pure ions. In addition, it also accurately controls the ion concentration, depth, and distribution of doped ions in the implanted target such as single crystal, and the results have good repeatability. , Our group successfully modified the properties of several halide perovskite single crystals and other semiconductors by metal ion implantation, which show that metal ion implantation can improve the light absorption of halide perovskite materials, thus enhancing the device performance. ,, …”

“…40,41 Our group successfully modified the properties of several halide perovskite single crystals and other semiconductors by metal ion implantation, which show that metal ion implantation can improve the light absorption of halide perovskite materials, thus enhancing the device performance. 5,39,42 Herein, the centimeter-sized CsPbBr 3 single crystals are prepared by an antisolvent method, and Zr ion implantation is employed to modify the optoelectronic properties of CsPbBr 3 single crystals. We fabricated pristine CsPbBr 3 and Zr ion implanted CsPbBr 3 -based PDs to explore the influence of Zr ion implantation on device performance.…”