Sharp exponential band tails in highly disordered lead sulfide quantum dot arrays

被引：56

作者：

Erslev, Peter T. ^{[1
]}

Chen, Hsiang-Yu ^{[1
]}

Gao, Jianbo ^{[1
]}

Beard, Matthew C. ^{[1
]}

Frank, Arthur J. ^{[1
]}

van de Lagemaat, Jao ^{[1
]}

Johnson, Justin C. ^{[1
]}

Luther, Joseph M. ^{[1
]}

机构：

[1] Natl Renewable Energy Lab, Golden, CO 80401 USA

来源：

PHYSICAL REVIEW B | 2012年 / 86卷 / 15期

关键词：

PBSE NANOCRYSTAL SOLIDS; GAP ABSORPTION TAILS; PHASE-SHIFT ANALYSIS; TEMPERATURE-DEPENDENCE; SOLAR-CELLS; MODULATED-PHOTOCURRENT; ELECTRICAL-PROPERTIES; SURFACE-CHEMISTRY; URBACH TAIL; THIN-FILMS;

D O I：

10.1103/PhysRevB.86.155313

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We employ temperature-dependent, illumination intensity modulated photocurrent spectroscopy (IMPS) to investigate the intra-band-gap density of states in films of PbS quantum dots (QDs). Using both coplanar electrode and stacked photovoltaic device configurations, IMPS measurements of PbS QD arrays show evidence of carrier trapping in exponential band tails extending from the band edges into the gap. The band tails have characteristic energies near 14 meV, similar to those found in other larger grain, polycrystalline bulk semiconductors, rather than the large Urbach energies normally associated with nanocrystals and porous/polycrystalline films. This result helps explain recent success in using QD solids in device applications and indicates potential for QD materials to compete with bulk materials in semiconductor applications.

引用

页数：5

共 49 条

[1] Comparing Multiple Exciton Generation in Quantum Dots To Impact Ionization in Bulk Semiconductors: Implications for Enhancement of Solar Energy Conversion [J].