Insight into Air Degradation of Inverted Perovskite Solar Cells with Different Cathode Interlayers.

Air stability is a big challenge for inverted perovskite solar cells (IPVSCs). We focus on effect of a cathode interlayer (BCP or TOASiW) on air degradation of IPVSCs with an Al or Ag cathode. Combined measurements have been carried out to check the changes of the device electrical performance with exposure to air.

Tuning an Electrode Work Function Using Organometallic Complexes in Inverted Perovskite Solar Cells.

Low-work-function (WF) metals (including silver (Ag), aluminum (Al), and copper (Cu)) used as external cathodes in inverted perovskite solar cells (PSCs) encounter oxidation caused by air exposure and halogen-diffusion-induced corrosion, which threaten the long-term stability of the device. The cathode interlayer (CIL) has shown promise in reducing the metal WF and thus boosting the device power conversion efficiency (PCE). However, it remains a challenge for current CIL materials to enable high-WF metals (e.

Efficient Inverted Perovskite Solar Cells Enabled by Dopant-Free Hole-Transporting Materials Based on Dibenzofulvene-Bridged Indacenodithiophene Core Attaching Varying Alkyl Chains.

Inspired by the structural advantages of spiro-OMeTAD, which is the most commonly used hole-transporting material (HTM), two rationally designed HTMs with butterfly-shaped triarylamine groups based on dibenzofulvene-bridged indacenodithiophene (IDT) core (attaching hexyl and octyl chains) have been synthesized, namely, IT-C6 and IT-C8, respectively. Shorter alkyl-chain-based IT-C6 exhibits a marked increase in glass-transition temperature () of 105 °C, whereas IT-C8 shows a of 95 °C. Moreover, it is demonstrated that IT-C6 exhibits a higher hole-transporting mobility, more suitable band energy alignment, better interfacial contact, and passivation effect.

Revealing working mechanisms of PFN as a cathode interlayer in conventional and inverted polymer solar cells.

Energy level alignments at the PC71BM/PFN/Ag interface in conventional polymer solar cells (c-PSCs) and the ITO/PFN/PC71BM interface in inverted polymer solar cells (i-PSCs) are systematically investigated via ultraviolet photoelectron spectroscopy and by using the integer charge transfer (ICT) model. The findings demonstrate that PFN as a cathode interlayer is able to effectively reduce the electron extraction barriers from 0.72 eV to 0.

Alcohol-Soluble Isoindigo Derivative IIDTh-NSB as a Novel Modifier of ZnO in Inverted Polymer Solar Cells.

Alcohol-soluble isoindigo derivative with thiophene groups and sulfobetaine zwitterions, IIDTh-NSB was applied as a novel modifier of ZnO in inverted polymer solar cells (i-PSCs). When IIDTh-NSB (0.2 mg/mL) was spin-coated on ZnO as an electron transport layer (ETL), power conversion efficiency (PCE) of the PTB7:PCBM based i-PSCs reached 8.

High Performance Small-Molecule Cathode Interlayer Materials with D-A-D Conjugated Central Skeletons and Side Flexible Alcohol/Water-Soluble Groups for Polymer Solar Cells.

A new class of organic cathode interfacial layer (CIL) materials based on isoindigo derivatives (IID) substituted with pyridinium or sulfonate zwitterion groups were designed, synthesized, and applied in polymer solar cells (PSCs) with PTB7:PCBM (PTB7: polythieno[3,4-b]-thiophene-co-benzodithiophene and PCBM: [6,6]-phenyl C71-butyric acidmethyl ester) as an active layer. Compared with the control device, PSCs with an IID-based CIL show simultaneous enhancement of open-circuit voltage (V), short-circuit current (J), and fill factor (FF). Systematic optimizations of the central conjugated core and side flexible alcohol-soluble groups demonstrated that isoindigo-based CIL material with thiophene and sulfonate zwitterion substituent groups can efficiently enhance the PSC performance.

Aqueous Solution Processed Photoconductive Cathode Interlayer for High Performance Polymer Solar Cells with Thick Interlayer and Thick Active Layer.

An aqueous-solution-processed photoconductive cathode interlayer is developed, in which the photoinduced charge transfer brings multiple advantages such as increased conductivity and electron mobility, as well as reduced work function. Average power conversion efficiency over 10% is achieved even when the thickness of the cathode interlayer and active layer is up to 100 and 300 nm, respectively.