Initial Photocarrier Generation Process in Organic Photovoltaics Observed with Light‐Triggered Time‐Domain Reflectometry

Herein, a time‐resolved electrical measurement is developed to observe the transient impedance of organic photovoltaics (OPV) and traced the initial photocarrier generation dynamics with the time region from 10 ns to 190 μs. A light‐triggered time‐domain reflectometry is adopted to observe the initial carrier dynamics in OPV by synchronizing rectangular light pulses from LED with a transient impedance probe pulse. Both the rising and recovery processes of OPV are observed in detail. The time evolution of the photocarrier distribution is calculated based on the diffusion–recombination scheme and is discussed in the initial process of photocarrier generation.