Photocurrent in Metal-Halide Perovskite/Organic Semiconductor Heterostructures: Impact of Microstructure on Charge Generation Efficiency

Abstract

Hybrid organic−inorganic metal-halide perovskites have emerged as versatile materials for enabling low-cost, mechanically flexible optoelectronic applications. The progress has been commendable; however, technological breakthroughs have outgrown the basic understanding of processes occurring in bulk and at device interfaces. Here, we investigated the photocurrent at perovskite/organic semiconductor interfaces in relation to the microstructure of electronically active layers. We found that the photocurrent response is significantly enhanced in the bilayer structure as a result of a more efficient dissociation of the photogenerated excitons and trions in the perovskite layer. The increase in the grain size within the organic semiconductor layer results in reduced trapping and further enhances the photocurrent by extending the photocarriers' lifetime. The photodetector responsivity and detectivity have improved by 1 order of magnitude in the optimized samples, reaching values of 6.1 ± 1.1 A W −1 , and 1.5 × 10 11 ± 4.7 × 10 10 Jones, respectively, and the current−voltage hysteresis has been eliminated. Our results highlight the importance of fine-tuning film microstructure in reducing the loss processes in thin-film optoelectronics based on metal-halide semiconductors and provide a powerful interfacial design method to consistently achieve high-performance photodetectors.

Oriented Growth of Thin Films of Covalent Organic Frameworks with Large Single-Crystalline Domains on the Water Surface

“…The less the defects, the longer the lifetime for charge carriers, and therefore a better conductivity was obtained. 35 To extract the charge carrier mobility of the film of COF-2,5-Ph, the current versus ramping bias voltage curve was obtained at the points with the peak current value in different crystalline domains (Figure 4d), in which the Schottky contact behavior between the probe and the film on ITO was clearly observed. The vertical semiconducting behavior could be analyzed by the space charge limited current (SCLC) model.…”

“…It could be inferred that layer stacking can anneal the defects in each layer as far as they do not overlap with each other and flat areas typically have less defects. The less the defects, the longer the lifetime for charge carriers, and therefore a better conductivity was obtained …”

Enhancing the performance of photoelectrochemical glucose sensorviathe electron cloud bridge of Au in SrTiO3/PDA electrodes

“…A low-impedance interface constructed between SrTiO 3 and PDA can remarkably improve the transmission efficiency of novel inorganic–organic interfaces. Similarly, Colin Tyznik et al 16 improved the charge separation efficiency by constructing a heterojunction between metal–halide perovskite and organic semiconductor. Constructing a conductive channel between platinum nanoparticles and graphitic carbon can improve the charge-separation ability of the material.…”

Switched‐On: Progress, Challenges, and Opportunities in Metal Halide Perovskite Transistors

“…[2,5,74] A particularly exciting example is the phototransistor: similar to the case of photodiodes and photoconductors, in phototransistors light absorption generates excitons and trions in the perovskite layer, which dissociate in the presence of an external electric field, resulting in free charges that are collected at the electrodes as photocurrent. [186,187] In addition, phototransistors modulate the signal current via the gate-source voltage, allowing for a higher sensitivity compared to the two terminal photodetectors. In this section, we will summarize the most notable developments in perovskite phototransistors.…”