Quantum Dot‐Siloxane Anchoring on Colloidal Quantum Dot Film for Flexible Photovoltaic Cell

Abstract

Lead sulfide (PbS) colloidal quantum dots (CQDs) are promising materials for next‐generation flexible solar cells because of near‐infrared absorption, facile bandgap tunability, and superior air stability. However, CQD devices still lack enough flexibility to be applied to wearable devices owing to the poor mechanical properties of CQD films. In this study, a facile approach is proposed to improve the mechanical stability of CQDs solar cells without compromising the high power conversion efficiency (PCE) of the devices. (3‐aminopropyl)triethoxysilane (APTS) is introduced on CQD films to strengthen the dot‐to‐dot bonding via QD‐siloxane anchoring, and as a result, crack pattern analysis reveals that the treated devices become robust to mechanical stress. The device maintains 88% of the initial PCE under 12 000 cycles at a bending radius of 8.3 mm. In addition, APTS forms a dipole layer on CQD films, which improves the open circuit voltage (VOC) of the device, achieving a PCE of 11.04%, one of the highest PCEs in flexible PbS CQD solar cells.

Colloidal quantum dot for infrared-absorbing solar cells: State-of-the-art and prospects

“…In addition to the development of flexible substrates in CQDSCs, improving the mechanical robustness of CQD solid films turned out as another key issue for achieving high-performance flexible CQDSCs. The conventional ligand-exchange procedure for CQDs generally aimed at replacing the long-chain OA ligands with shorter ones to ameliorate the charge transport properties of CQD solid films at the expense of their mechanical properties [280]. Therefore, Lee et al introduced (3-aminopropyl)triethoxysilane (APTS) onto the CQD films to strengthen the dot-to-dot bonding through the Pb-O-Si bonds between CQDs and siloxane [281].…”

Integration of PbS Quantum Dots with 3D-Graphene for Self-powered Broadband Photodetectors in Image Sensors

“…Existing NIR PDs, exemplified by the InGaAs detector, have been applied in infrared civilian markets and military fields due to their adjustable band gap. However, the limited operating wavelength range (800 nm to 1.7 μm) and process shortcomings (difficult to prepare large size) have seriously hindered its performance and application expansion. , 3D-graphene, as a derivative of 2D-graphene, not only maintains the extraordinary properties of graphene, such as high electrical conductivity and wide-band photoresponse, but more importantly, its unique interlayer interconnecting structure greatly improves light absorption. − In addition, PbS QDs are also promising candidates for NIR photovoltaic applications owing to their straightforward solution processing, size-tunable bandgap, and excellent photovoltaic properties. , …”

“…9−11 In addition, PbS QDs are also promising candidates for NIR photovoltaic applications owing to their straightforward solution processing, size-tunable bandgap, and excellent photovoltaic properties. 12,13 In this work, 3D-graphene has been synthesized in situ on Si substrate via plasma-assisted chemical vapor deposition (PACVD), followed by modification PbS QDs. This approach was adopted to create a high-performance, wide-band response and long-term stability NIR PD dispensed with cooling.…”