Efficient light harvesting and carrier transport in PbS quantum dots/silicon nanotips heterojunctions

Abstract

Light harvesting from nanocomposites consisting of silicon (Si) nanotips and PbS quantum dots (QDs) has been investigated. We show that Si nanotips provide direct carrier transport paths, additional interfacial area and light trapping. We observe that there is a dramatic enhancement in short-circuit current (from 9.34 to 14.17 mA cm −2) with nanotips structure than that of the bulk Si wafer. In addition, with an additional electron blocking layer, the photovoltaic performance can be further increased. The nanocomposites consisting of QDs and Si nanotips therefore open a promising route for efficient light harvesting from visible to infrared with improved power conversion efficiency.

The Silicon:Colloidal Quantum Dot Heterojunction

“…The combination of CQDs and silicon has primarily been used to enhance absorption of structured p–n silicon solar cells in the visible range . c‐Si:CQD rectifying solar cells have been presented, but to date exhibit no extraction of carriers generated using subsilicon‐bandgap (>1.1 μm) illumination . The reasons for this failure of the c‐Si:CQD heterointerface have, to this point, been unexplored and unexplained.…”

Pulsed Laser Ablation based Direct Synthesis of Single‐Wall Carbon Nanotube/PbS Quantum Dot Nanohybrids Exhibiting Strong, Spectrally Wide and Fast Photoresponse

“…Indeed, the presence of CNTs and/or QDs in such devices has been shown to be associated with significant gains in photocharges creation/collection and/or the ability to harvest photons over an extended part of the solar spectrum 6–10. A salient example is that of PbS‐QDs, which combine the two following features: (i) the quantum confinement‐induced tunability of their band gap over an energy range as wide as 0.4–2 eV,11, 12 and (ii) the multiple excitons generation (MEG) phenomenon, which has been recently invoked to be responsible for the enhanced performance of PbS‐QD based PV and PC devices 13–15. Thus, several PC devices where PbS‐QDs act as sensitizers, in conjunction with fullerene derivatives, have been shown to exhibit an interesting photoresponse (defined as I ph / I d , where I ph is the photocurrent obtained by subtracting the dark current ( I d ) from the current measured under illumination ( I i )) 16–17.…”

Enhanced charge carrier injection in heterojunction organic field-effect transistor by inserting an MoO 3 buffer layer

“…[10−12] Among many advanced OFET structures, the organic semiconductor heterojunction is an effective architecture to improve the performance of OFET, [6,13,14] which has also been extensively utilized in organic light-emitting diodes (OLEDs) [15,16] and organic photovoltaic cells (OSCs). [17,18] The reason is that the heterojunction structure in OFET possesses the advantage of increasing the conductivity of the active layer, morphological matching between different organic films, and manipulating the interface molecular level alignment.…”