Nitrogen-Doped Mesoporous Carbons as Counter Electrodes in Quantum Dot Sensitized Solar Cells with a Conversion Efficiency Exceeding 12%

Abstract

The exploration of catalyst materials for counter electrodes (CEs) in quantum dot sensitized solar cells (QDSCs) that have both high electrocatalytic activity and low charge transfer resistance is always significant yet challenging. In this work, we report the incorporation of nitrogen heteroatoms into carbon lattices leading to nitrogen-doped mesoporous carbon (N-MC) materials with superior catalytic activity when used as CEs in Zn-Cu-In-Se QDSCs. A series of N-MC materials with different nitrogen contents were synthesized by a colloidal silica nanocasting method. Electrochemical measurements revealed that the N-MC with a nitrogen content of 8.58 wt % exhibited the strongest activity in catalyzing the reduction of a polysulfide redox couple (S/S), and therefore, the corresponding QDSC device showed the best photovoltaic performance with an average power conversion efficiency (PCE) of 12.23% and a certified PCE of 12.07% under one full sun illumination, which is a new PCE record for quantum dot based solar cells.

Improved Processability and Efficiency of Colloidal Quantum Dot Solar Cells Based on Organic Hole Transport Layers

“…[3][4][5][6][7][8][9][10][11][12] In the research on CQD surface engineering, effective halide-passivation successfully reduced the trap state density of CQDs, achieving increased charge drift and charge diffusion. [3][4][5][6][7][8][9][10][11][12] In the research on CQD surface engineering, effective halide-passivation successfully reduced the trap state density of CQDs, achieving increased charge drift and charge diffusion.…”

Boosting the Performance of Environmentally Friendly Quantum Dot‐Sensitized Solar Cells over 13% Efficiency by Dual Sensitizers with Cascade Energy Structure

“…[1][2][3][4] In the past few years, the power conversion efficiency (PCE) of liquid-junction QDSCs has been improved from less than 5% to over 12%, [5][6][7][8] which is still below with those of the emerging inorganic photovoltaic technologies such as perovskite CsPbI 3 QD-based solar cells. [1][2][3][4] In the past few years, the power conversion efficiency (PCE) of liquid-junction QDSCs has been improved from less than 5% to over 12%, [5][6][7][8] which is still below with those of the emerging inorganic photovoltaic technologies such as perovskite CsPbI 3 QD-based solar cells.…”

“…[8] The J-V curves of the champion cells for each series under AM 1.5G 1 sun irradiation (100 mW cm −2 ) are shown in Figure 2b, and the main photovoltaic parameters are listed in Table 1. Typical sandwichtype solar cells were fabricated employing a Ti mesh supported mesoporous carbon (MC/Ti) counter electrode and a polysulfide electrolyte redox couple.…”

Metal–Ligand Complex‐Induced Ultrafast Charge‐Carrier Relaxation and Charge‐Transfer Dynamics in CdX (X=S, Se, Te) Quantum Dots Sensitized with Nitrocatechol

“…It is expected that the efficiency of quantum dot solar cell (QDSC) can be as high as 31 % . However till now the highest conversion efficiency recorded is around 12 % . It shows that a lot of improvement is still needed to design higher efficient QDSC and reasons behind the lower efficiency need to be addressed properly.…”

“…[12] However till now the highest conversion efficiency recorded is around 12 %. [13] It shows that al ot of improvement is still needed to design higher efficient QDSCa nd reasons behind the lower efficiency need to be addressed properly.T he first andf oremost process in any QDSC is the absorption of solar radiation by QDs materi-als to generate charge carriers. To get high efficiency QDSC it is extremely important to extract thesep hoto-generated chargec arriers (both electron and holes)b efore their recombination.Anumber of molecular adsorbates have been used for this purpose but it has been observedt hat hole transfer [14,15] rate is much slower as compared to electron transfer rate [16,17] and is one of the main reasons forl ower efficiency of QDSC.…”