Guanidinium‐Assisted Surface Matrix Engineering for Highly Efficient Perovskite Quantum Dot Photovoltaics

Abstract

A ligand-assisted matrix to regulate surface and packing states of perovskite quantum dots (QDs) is demonstrated, which involves a ligand exchange and a mild thermal annealing process that are triggered by guanidinium thiocyanate. Consequently, the CsPbI 3 QD solar cells (QDSCs) deliver a champion power conversion efficiency of 15.21%, which is the highest report among all CsPbI 3 QDSCs.

In Situ Ligand Bonding Management of CsPbI3 Perovskite Quantum Dots Enables High‐Performance Photovoltaics and Red Light‐Emitting Diodes

“…Finally,t odemonstrate the merit of L-PHE passivated CsPbI 3 QDs for application in optoelectronic devices,w ef abricated QD solar cells and red LEDs using CsPbI 3 QDs w/wo L-PHE passivation as light absorbing and luminescent layer, Figure 5a,t he solar cell device architecture consists of al ayered structure of FTO/TiO 2 / CsPbI 3 QDs/PTAA/MoO 3 /Ag, [31] in which TiO 2 and PTAA are the electron-transport and hole-transport layer, respectively.A ss hown in Figure 5b,t he pristine CsPbI 3 QD solar cells without any additional treatment show ab est efficiency of 13.59 %, similar to previous reports. [27][28][29][30][31][32][33][34] Forthe in situ L-PHE treated QDs,a fter optimization, an enhanced shortcircuit current density (J sc )of15.23 mA cm À2 ,asimilar opencircuit voltage (V oc )of1.23 Vand afill factor (FF) of 0.78 are achieved, giving an improved PCE of 14.62 %, which is among the highest reported PCE values for CsPbI 3 QDs solar cells (Supporting Information, Table S1). Both devices exhibit similar J-V hysteresis (Supporting Information, Figure S8).…”

“…An efficiency of 10.77 % was reported, and these devices also function as LEDs with low turn‐on voltage and tunable emission. The PV efficiency of CsPbI 3 QDs was further improved 15 % via doping and solid state passivation strategies [26–33] . Meanwhile, these strategies were also employed to develop efficient red LED devices using CsPbI 3 QDs, the highest external quantum efficiency (EQE) value of 5.92 % has been reported [34–36] .…”

In Situ Ligand Bonding Management of CsPbI3 Perovskite Quantum Dots Enables High‐Performance Photovoltaics and Red Light‐Emitting Diodes

“…Finally,t odemonstrate the merit of L-PHE passivated CsPbI 3 QDs for application in optoelectronic devices,w e fabricated QD solar cells and red LEDs using CsPbI 3 QDs w/ wo L-PHE passivation as light absorbing and luminescent layer, respectively.A si llustrated in Figure 5a,t he solar cell device architecture consists of al ayered structure of FTO/ TiO 2 /CsPbI 3 QDs/PTAA/MoO 3 /Ag, [31] in which TiO 2 and PTAA are the electron-transport and hole-transport layer, respectively.A ss hown in Figure 5b,t he pristine CsPbI 3 QD solar cells without any additional treatment show ab est efficiency of 13.59 %, similar to previous reports. [27][28][29][30][31][32][33][34] Forthe in situ L-PHE treated QDs,a fter optimization, an enhanced short-circuit current density (J sc )o f1 5.23 mA cm À2 ,asimilar open-circuit voltage (V oc )o f1 .23 Vand af ill factor (FF) of 0.78 are achieved, giving an improved PCE of 14.62 %, which is among the highest reported PCE values for CsPbI 3 QDs solar cells (Supporting Information, Table S1). Both devices exhibit similar J-V hysteresis ( Supporting Information, Figure S8).…”

Flexible and efficient perovskite quantum dot solar cells via hybrid interfacial architecture

“…The best PbS QD solar cell has achieved a power conversion e ciency (PCE) of 13.8% due to improvements in surface passivation and device structure 18 . More recently, all-inorganic CsPbI 3 QDs have emerged as a rising star for photovoltaic applications because of their outstanding properties including phase stability that is otherwise not achievable in bulk thin-lm form, and high photoluminescence (PL) quantum yields due to impressive defect tolerance 19-22 . Advances in CsPbI 3 QD solar cells have enabled high e ciency over 15% to be achieved, showing great potential for photovoltaics [23][24] . Importantly, fabrication of perovskite QDs involve colloidal synthesis and processing using industrially friendly solvents at room temperature, opening a new platform for developing high performance QD optoelectronic devices [25][26][27][28][29] .…”