Ambient Stable and Efficient Monolithic Tandem Perovskite/PbS Quantum Dots Solar Cells via Surface Passivation and Light Management Strategies

Abstract

Here, highly efficient and stable monolithic (2-terminal (2T)) perovskite/PbS quantum dots (QDs) tandem solar cells are reported, where the perovskite solar cell (PSC) acts as the front cell and the PbS QDs device with a narrow bandgap acts as the back cell. Specifically, ZnO nanowires (NWs) passivated by SnO 2 are employed as an electron transporting layer for PSC front cell, leading to a single cell PSC with maximum power conversion efficiency (PCE) of 22.15%, which is the most efficient NWs-based PSCs in the literature. By surface passivation of PbS QDs by CdCl 2 , QD devices with an improved opencircuit voltage and a PCE of 8.46% (bandgap of QDs: 0.92 eV) are achieved. After proper optimization, 2T and 4T tandem devices with stabilized PCEs of 17.1% and 21.1% are achieved, respectively, where the 2T tandem device shows the highest efficiency reported in the literature for this design. Interestingly, the 2T tandem cell shows excellent operational stability over 500 h under continuous illumination with only 6% PCE loss. More importantly, this device without any packaging depicts impressive ambient stability (almost no change) after 70 days in an environment with controlled 65% relative humidity, thanks to the superior air stability of the PbS QDs.

Performance Improvement of Perovskite Solar Cells by Interactions between Nano‐Sized Quantum Dots and Perovskite

“…Thankfully, some effective methods have been developed and provide the potential in surpassing the theoretical efficiency limit by treating PSCs with QDs. [20,22,23]…”

“…In this PSC/QD 2T tandem device, a Cs 0.05 FA 0.8 MA 0.15 PbI 2.55 Br 0.45 PSC is adopted as one subcell whilst a PbS QD cell passivated by CdCl 2 functions as the other subcell, as shown in Figure a. [ 23 ] Encouragingly, an impressive PCE of 17.1% has been yielded for the PSC/QD 2T tandem cell, demonstrating the prospect of this 2T tandem device with QD subcell that enables extended light absorption (Figure 8b). The other tandem structure of PSC/QD solar cells, 4T configuration, can be fabricated in a much simpler manner due to the easy operation of the mechanical stack and connection of two subcells and no current‐matching limitation, enabling higher device performance.…”

Biosynthesis of quantum dots and their usage in solar cells: insight from the novel researches

“…Recently, QDs research aimed at developing good quality QDs for solar cell and biomedical devices and applications [24][25][26][27][28][29][30]. Each application requires unique parameters to Carbon-QDs emit photons that spans from the ultraviolet to infrared energy, at a variance of semiconductor counterpart the photoluminescence comes from different oxidation of graphene that introduced discrete energy levels [19] achieve a good detection limit, such as excitation energy, emission wavelength and yield.…”

Atomic Layer Engineering of Aluminum‐Doped Zinc Oxide Films for Efficient and Stable Perovskite Solar Cells

“…[30][31][32][33][34] It has been proven that the deprotonation of the methylammonium cation and the formation of zinc hydroxide accelerate the perovskite decomposition. [35,36] To overcome this obstacle, the ZnO/perovskite interface instability can be mitigated by the interface passivation of the ZnO surface with various org anic [33,34,37,38,39,[40][41][42] or inorganic [14,[43][44][45][46][47][48] modification layers, and doping of ZnO bulk with metal heteroatoms. [49][50][51] In the latter case, aluminum (Al) doping not only enhances the stability of the ZnO/perovskite interface by decreasing the basic property of ZnO [52] but also greatly improves its carrier concentration and electron mobility.…”