Surface‐Engineered Ti₃C₂T_x with Tunable Work Functions for Highly Efficient Polymer Solar Cells

Abstract

Ti3C2Tx, as a newly investigated 2D material, has gained great attention owing to its metallic conductivity, tunable work function (WF), and unique electrical property. However, its WF can be further adjusted to meet the needs of optoelectronic devices. Here, surface‐engineered Ti3C2Tx is fabricated with tunable WF by treating with ethanolamine and rhodium chloride (RhCl3). Ethanolamine treated Ti3C2Tx can induce the chemical adsorption of NH2 on Ti3C2Tx with hydrogen‐bonding, which causes the decreased WF, while chemical doping with RhCl3 leads to the improvement of WF, which is achieved by the downshift of Femi level of Ti3C2Tx. Moreover, the ethanolamine and RhCl3 can effectively passivate the vacancies of Ti. As such, the surface‐engineered Ti3C2Tx is more suitable as buffer layer for polymer solar cells (PSCs) by enhancing the interfacing characteristics of the Ti3C2Tx/active layer. The PSCs with engineered Ti3C2Tx for electron or hole transport layers can exhibit a power conversion efficiency of 15.88% or 15.54%. These efficiencies can be compared with those of devices with a conventional transport layer. This work provides a facile strategy to realize the work function tunability of Ti3C2Tx, and also shows that the tuned Ti3C2Tx has a certain application prospect in photovoltaic devices.

Single‐Layer Carbon Nitride as an Efficient Metal‐Free Organic Electron‐Transport Material with a Tunable Work Function

“…5 eV by modifications with ethanolamine and/or Rh 3+ . [ 58 ] The WF of Nb 2 CT x MXene sheets was tuned between ca. 4.3 and ca.…”

Dual-layer synergetic optimization of high-efficiency planar perovskite solar cells using nitrogen-rich nitrogen carbide as an additive

“…S8 and S9† show that the bandgap energies of the prepared perovskite films are the same about 1.60 eV, while the slightly upward shifted Fermi level in the perovskite@g-C 3 N 5 film is attributed to the passivation effect of the amino group of g-C 3 N 5 , and Table S3† further summarizes the relevant energy band information. 39,40…”

“…S8 and S9 † show that the bandgap energies of the prepared perovskite lms are the same about 1.60 eV, while the slightly upward shied Fermi level in the perovskite@g-C 3 N 5 lm is attributed to the passivation effect of the amino group of g-C 3 N 5 , and Table S3 † further summarizes the relevant energy band information. 39,40 A series of photoelectrochemical measurements were executed to further explicate the internal properties of the resultant perovskite lms. The surface properties of perovskite lms were inspected by performing the XPS strategy.…”

Optically Active MXenes in Van der Waals Heterostructures

“…For instance, Mariano et al determined the WF of Ti 3 C 2 T x by KPFM to be 5.28 eV, which is considerably higher than the value ranging between 3.40 and 4.85 eV obtained by UPS. [119,[123][124][125][126][127] In addition, the modification of MXenes' WF has been also experimentally proved by different treatments, including thermal annealing, [128] UV-ozone treatment, [126] doping, [124] and grafting organic molecules. [125] For more details, we have summarized the WFs of various MXenes with different surface terminations in Table S2 (Supporting Information).…”