Phosphorene Nanoribbon-Augmented Optoelectronics for Enhanced Hole Extraction

Abstract

Phosphorene nanoribbons (PNRs) have been widely predicted to exhibit a range of superlative functional properties; however, because they have only recently been isolated, these properties are yet to be shown to translate to improved performance in any application. PNRs show particular promise for optoelectronics, given their predicted high exciton binding energies, tunable bandgaps, and ultrahigh hole mobilities. Here, we verify the theorized enhanced hole mobility in both solar cells and spacecharge-limited-current devices, demonstrating the potential for PNRs improving hole extraction in universal optoelectronic applications. Specifically, PNRs are demonstrated to act as an effective charge-selective interlayer by enhancing hole extraction from polycrystalline methylammonium lead iodide (MAPbI 3 ) perovskite to the poly(triarylamine) semiconductor. Introducing PNRs at the hole-transport/MAPbI 3 interface achieves fill factors above 0.83 and efficiencies exceeding 21% for planar p−i−n (inverted) perovskite solar cells (PSCs). Such efficiencies are typically only reported for single-crystalline MAPbI 3 -based inverted PSCs. Methylammonium-free PSCs also benefit from a PNR interlayer, verifying applicability to architectures incorporating mixed perovskite absorber layers. Device photoluminescence and transient absorption spectroscopy are used to demonstrate that the presence of the PNRs drives more effective carrier extraction. Isolation of the PNRs in space-charge-limited-current hole-only devices improves both hole mobility and conductivity, demonstrating applicability beyond PSCs. This work provides primary experimental evidence that the predicted superlative functional properties of PNRs indeed translate to improved optoelectronic performance.

Fluorine Functionalized MXene QDs for Near‐Record‐Efficiency CsPbI3 Solar Cell with High Open‐Circuit Voltage

“…The current‐voltage ( J–V ) curves at high voltage are fitted by J (V) = (9/8) εε 0 µV 2 /d 3 , where ε is the dielectric constant and d is the film thickness of Spiro‐OMeTAD. [ 30 ] The hole mobility of Spiro‐OMeTAD without Ti 3 C 2 F x QDs is 1.59 × 10 –4 cm 2 V –1 S –1 , which increases to 3.50 × 10 –4 cm 2 V –1 S –1 after Ti 3 C 2 F x QDs treatment. Therefore, Ti 3 C 2 F x QDs treatment can not only improve the electrical properties of perovskite, but also enhance the mobility and hole extraction ability of Spiro‐OMeTAD.…”

PTAA as Efficient Hole Transport Materials in Perovskite Solar Cells: A Review

“…[187] Improvement on current output and FF was reported. [187] Figure 5. Top-view scanning electron microscopy (SEM) images of the perovskite film on a) PTAA and b) PTAA/PFN substrates.…”

“…[ 68 ] Phosphorene nanoribbons have been deployed as interlayers between the PTAA and the perovskite to assist carrier extraction. [ 187 ] Improvement on current output and FF was reported. [ 187 ]…”

Enhanced Spin Thermopower in Phosphorene Nanoribbons via Edge-State Modifications

“…Ezawa [ 33 ] and Sisakht et al [ 34 ] have explained the presence of the quasi-flat band in the tight-binding model; it was shown that the quasi-flat band can be controlled by a transverse electric field along the width of the nanoribbon. The individual two-dimensional phosphorene nanoribbons have been successfully synthesized by Watts et al [ 35 ], which has already stimulated the experimental research on phosphorene-nanoribbon-based solar cells [ 36 ]. Graphene nanoribbons with zigzag edges are demonstrated to be unstable, but zigzag phosphorene nanoribbons are stable.…”