Heteroepitaxy of high-quality GaN-based heterostructures with tunable band alignment and optical pro-perties is of central importance for their applications in electronics and optoelectronics.Incommensurate material g...Heteroepitaxy of high-quality GaN-based heterostructures with tunable band alignment and optical pro-perties is of central importance for their applications in electronics and optoelectronics.Incommensurate material growth on the GaN substrate with an abrupt interface is still a challenge due to the formation of high-density interface defects and structural disordering induced by the lattice mismatch.Herein,we report the heteroepitaxial growth of high-quality uniform CsPb(Br_(x)Cl_(1−x))_(3)perovskite alloy nanoplatelets on the c-GaN substrate with fully tunable compositions(0≤x≤1)via space-confined chemical vapor deposition.The formation of large-mismatch CsPb(Br_(x)Cl_(1−x))_(3)/GaN heterostructures arises from relatively weak interfacial interactions(0.58-0.61 J m^(−2))that reduce the impact of the lattice mismatch on the growth.The CsPb(Br_(x)Cl_(1−x))_(3)/GaN heterostructures exhibit type-Ⅱ band alignment with a tunable valence band offset from 0.85 to 1.34 eV and a conduction band offset from 0.45 to 0.61 eV,respectively.These heterostructures show remarkable photoluminescence quenching and reduced exciton lifetimes as com-pared with the CsPb(Br_(x)Cl_(1−x))_(3)nanoplatelets grown on mica,which are attributed to the enhanced carrier separation and extraction efficiencies.These findings of this work provide an efficient strategy for the advancement of the versatile synthesis of large-mismatch perovskite/GaN heterostructures and exhibit their excellent potential for various functional optoelectronics.展开更多
基金supported in part by the Natural Science Foundation of Zhejiang Province(Grant No.LZ22F040003 and LY22A040002)the National Natural Science Foundation of China(Grant No.62174151 and 61775201)computational resources from the Shanghai Supercomputer Center are acknowledged.
文摘Heteroepitaxy of high-quality GaN-based heterostructures with tunable band alignment and optical pro-perties is of central importance for their applications in electronics and optoelectronics.Incommensurate material growth on the GaN substrate with an abrupt interface is still a challenge due to the formation of high-density interface defects and structural disordering induced by the lattice mismatch.Herein,we report the heteroepitaxial growth of high-quality uniform CsPb(Br_(x)Cl_(1−x))_(3)perovskite alloy nanoplatelets on the c-GaN substrate with fully tunable compositions(0≤x≤1)via space-confined chemical vapor deposition.The formation of large-mismatch CsPb(Br_(x)Cl_(1−x))_(3)/GaN heterostructures arises from relatively weak interfacial interactions(0.58-0.61 J m^(−2))that reduce the impact of the lattice mismatch on the growth.The CsPb(Br_(x)Cl_(1−x))_(3)/GaN heterostructures exhibit type-Ⅱ band alignment with a tunable valence band offset from 0.85 to 1.34 eV and a conduction band offset from 0.45 to 0.61 eV,respectively.These heterostructures show remarkable photoluminescence quenching and reduced exciton lifetimes as com-pared with the CsPb(Br_(x)Cl_(1−x))_(3)nanoplatelets grown on mica,which are attributed to the enhanced carrier separation and extraction efficiencies.These findings of this work provide an efficient strategy for the advancement of the versatile synthesis of large-mismatch perovskite/GaN heterostructures and exhibit their excellent potential for various functional optoelectronics.
