Dynamics of recombination processes in PbI2 nanocrystals embedded in porous silica films

被引:53
作者
Dag, I
Lifshitz, E
机构
[1] TECHNION ISRAEL INST TECHNOL,DEPT CHEM,IL-32000 HAIFA,ISRAEL
[2] TECHNION ISRAEL INST TECHNOL,INST SOLID STATE,IL-32000 HAIFA,ISRAEL
关键词
D O I
10.1021/jp952863y
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The present paper discusses the dynamics of recombination processes in PbI2 nanocrystals embedded in porous silica films. The photoluminescence (PL) spectrum of the samples consists of three bands: an exciton band near 2.5 eV and two deeper bands centered at 2.44 eV (L band) and 2.03 eV (G band). The L band relates to bulk defects in the internal volume of the particles, while the G band relates to surface defects. The dynamics of the different recombination events was investigated by continuous and time-resolved PL techniques. All three peaks exhibit a complex decay, which consists of several multiexponential components, progressing from nanoseconds to microseconds. The exciton has an additional fast intrinsic decay component in the sub-nanosecond time scale that may be superradiative in nature. The analysis of the decay dynamics in the nanosecond regime requires a distributed kinetic model, based on the Kohlraushch-Williams-Watts (KWW) stretched exponential function. The experimental results are consistent with detrapping and repopulation professes, in which excited carriers can relax to lower lying surface states (associated with the G band). Thermal detrapping from these states and repopulation of the exciton and L band states results in a long multiexponential decay. The microsecond decay of L and G bands obeys a donor-acceptor recombination characteristic dynamics.
引用
收藏
页码:8962 / 8972
页数:11
相关论文
共 58 条
[51]   OPTICAL TRANSIENT BLEACHING OF QUANTUM-CONFINED CDS CLUSTERS - THE EFFECTS OF SURFACE-TRAPPED ELECTRON-HOLE PAIRS [J].
WANG, Y ;
SUNA, A ;
MCHUGH, J ;
HILINSKI, EF ;
LUCAS, PA ;
JOHNSON, RD .
JOURNAL OF CHEMICAL PHYSICS, 1990, 92 (11) :6927-6939
[52]   CHEMICAL EFFECTS ON THE OPTICAL-PROPERTIES OF SEMICONDUCTOR PARTICLES [J].
WANG, Y ;
HERRON, N .
JOURNAL OF PHYSICAL CHEMISTRY, 1987, 91 (19) :5005-5008
[53]   PHOTOLUMINESCENCE AND RELAXATION DYNAMICS OF CDS SUPERCLUSTERS IN ZEOLITES [J].
WANG, Y ;
HERRON, N .
JOURNAL OF PHYSICAL CHEMISTRY, 1988, 92 (17) :4988-4994
[54]   QUANTUM SIZE EFFECTS IN SIMPLE COLORED GLASS [J].
WARNOCK, J ;
AWSCHALOM, DD .
PHYSICAL REVIEW B, 1985, 32 (08) :5529-5531
[55]   LUMINESCENCE OF DEFECT-INDUCED LOCALIZED EXCITON-STATES IN PBI2 [J].
WATANABE, M ;
HAYASHI, T ;
KATO, R .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1990, 59 (12) :4526-4533
[56]   COLLOIDAL SEMICONDUCTOR Q-PARTICLES - CHEMISTRY IN THE TRANSITION REGION BETWEEN SOLID-STATE AND MOLECULES [J].
WELLER, H .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1993, 32 (01) :41-53
[57]   NON-SYMMETRICAL DIELECTRIC RELAXATION BEHAVIOUR ARISING FROM A SIMPLE EMPIRICAL DECAY FUNCTION [J].
WILLIAMS, G ;
WATTS, DC .
TRANSACTIONS OF THE FARADAY SOCIETY, 1970, 66 (565P) :80-+
[58]   STOKES AND ANTI-STOKES D-A PAIR LUMINESCENCES IN PBI2 [J].
YAMAZAKI, S ;
GOTO, T .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1982, 51 (10) :3228-3235