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P-Type Doping of Mixed Tin-Lead Halide Perovskites Using Electron Transfer to Mo(tfd-COCF3)3 and F4TCNQ
Migon Choi1, Nelson Rivera2, Steven P Harvey3
1Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States.
ACS Applied Materials & Interfaces
|December 10, 2025
Summary
This study explores p-type doping of mixed tin-lead halide perovskites using molecular dopants. Researchers achieved significant increases in carrier density and conductivity, paving the way for less toxic optoelectronics.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Optoelectronics
Background:
- Mixed tin-lead halide perovskites offer a less toxic alternative to lead-based perovskites for optoelectronic devices.
- Electron-transfer doping is a method to tune perovskite electronic properties without altering crystal structure.
- Limited comparative studies exist on molecular dopants for these perovskite systems.
Purpose of the Study:
- To investigate the p-type electron-transfer doping of methylammonium lead tin iodide (MAPb0.5Sn0.5I3) perovskites.
- To compare the effectiveness of two molecular dopants, F4TCNQ and Mo(tfd-COCF3)3, for doping this perovskite system.
- To analyze the impact of doping on carrier density and conductivity.
Main Methods:
- Utilized a sequential deposition approach, applying the dopant after perovskite film formation.
- Employed F4TCNQ and Mo(tfd-COCF3)3 as p-type molecular dopants.
- Measured carrier density and conductivity changes in doped versus undoped MAPb0.5Sn0.5I3 films.
Main Results:
- Achieved up to a 3-order of magnitude increase in carrier density.
- Observed up to a 2-order of magnitude increase in conductivity compared to undoped samples.
- Reported similar doping efficiencies for F4TCNQ (0.031%) and Mo(tfd-COCF3)3 (0.024%), suggesting dopant incorporation differences influence effectiveness.
Conclusions:
- P-type electron-transfer doping is effective in enhancing the conductivity of mixed tin-lead halide perovskites.
- F4TCNQ and Mo(tfd-COCF3)3 are viable molecular dopants for MAPb0.5Sn0.5I3.
- Dopant incorporation during spin coating significantly affects doping outcomes.
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