Performance enhancement of ZnO nanowires/PbS quantum dot depleted bulk heterojunction solar cells with an ultrathin Al ₂ O ₃ interlayer

Abstract

Depleted bulk heterojunction (DBH) PbS quantum dot solar cells (QDSCs), appearing with boosted short-circuit current density (J sc ), represent the great potential of solar radiation utilization, but suffer from the problem of increased interfacial charge recombination and reduced open-circuit voltage (V oc ). Herein, we report that an insertion of ultrathin Al 2 O 3 layer (ca. 1.2 Å thickness) at the interface of ZnO nanowires (NWs) and PbS quantum dots (QDs) could remarkably improve the performance of DBH-QDSCs fabricated from them, i.e., an increase of V oc from 449 mV to 572 mV, J sc from 21.90 mA/cm 2 to 23.98 mA/cm 2 , and power conversion efficiency (PCE) from 4.29% to 6.11%. Such an improvement of device performance is ascribed to the significant reduction of the interfacial charge recombination rate, as evidenced by the light intensity dependence on J sc and V oc , the prolonged electron lifetime, the lowered trap density, and the enlarged recombination activation energy. The present research therefore provides an effective interfacial engineering means to improving the overall performance of DBH-QDSCs, which might also be effective to other types of optoelectronic devices with large interface area.

Ultraviolet irradiation dosimeter based on persistent photoconductivity effect of ZnO*

“…Wide bandgap semiconductor ZnO (3.37 eV) has been widely applied in UV photodetectors. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] Meanwhile, the PPC effect has been reported in ZnO microwires (MW) photodetectors due to the surface oxygen absorption/desorption related processes. [32] In this paper, the unique characteristics of the PPC effect are utilized to monitor the accumulative exposure.…”

High-quality CdS quantum dots sensitized ZnO nanotube array films for superior photoelectrochemical performance

“…), element doping (C, [22,23] N, [24,25] Ni, [26] Na, [27] etc. ), sensitization of quantum dots (QDs) with narrow band gap materials (PbS, [28] CdS, [29] CdSe, [30] etc. ), and so on.…”

Effect of Mn-substitution on impedance spectroscopy and magnetic properties of Al-doped ZnO nanoparticles

“…It is inexpensive, non-toxic, abundant in nature, chemically stable, and is easy to synthesize for various morphologies such as nanoparticles (NPs), nanorods, nanowires, etc, due to its chemical behaviors [3,4]. Furthermore, ZnO has numerous applications such as gas sensors [5], optoelectronic devices [6], solar cells [7], varistors [8], and acoustic devices [9]. It is necessary to investigate the dielectric properties of materials, as this is an important physical characteristic.…”