Yu Pingrong, Beard Matthew C, Ellingson Randy J, Ferrere Suzanne, Curtis Calvin, Drexler John, Luiszer Fred, Nozik Arthur J
Center for Basic Sciences, National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
J Phys Chem B. 2005 Apr 21;109(15):7084-7. doi: 10.1021/jp046127i.
We report the absorption cross-section of colloidal InAs quantum dots of mean radii from 1.6 to 3.45 nm. We find excellent agreement between the measured results and calculated values based on a model of small-particle light absorption. The absorption cross-section per dot is 6.2 x 10(-16)R(3) cm(2) at 2.76 eV and 3.15 x 10(-16)R(1.28) cm(2) at the first-exciton absorption peak, with the dot radius R in nm. We find that the per-quantum-dot particle oscillator strength of the first-exciton transition is constant for all sizes studied. The radiative lifetime of the first exciton calculated from the oscillator strength increases with dot size and ranges from 4 ns for the smallest dots to 14 ns for the largest ones.
我们报告了平均半径在1.6至3.45纳米之间的胶体铟砷量子点的吸收截面。我们发现测量结果与基于小颗粒光吸收模型的计算值之间具有极好的一致性。在2.76电子伏特时，每个量子点的吸收截面为6.2×10⁻¹⁶R³平方厘米，在第一激子吸收峰处为3.15×10⁻¹⁶R¹·²⁸平方厘米，其中量子点半径R以纳米为单位。我们发现，对于所有研究的尺寸，第一激子跃迁的每个量子点的粒子振子强度是恒定的。根据振子强度计算出的第一激子的辐射寿命随量子点尺寸的增加而增加，范围从最小量子点的4纳秒到最大量子点的14纳秒。
