Collaborative Research: Interfacial Engineering for Stabilizing Hybrid Perovskites and Devices

Abstract Non-Technical Summary

Highly efficient and low-cost light emitting diodes (LEDs) are critical for the future energy landscape in the United States. They are widely used in displays and lighting. Current technologies use high temperature and high vacuum for materials processing and device fabrication, which are energy- and infrastructure-demanding.

In this project, LED devices based on a new type of semiconductors—the so-called organic-inorganic hybrid perovskites—will be studied. These materials exhibit excellent optical and optoelectronic properties required for LED applications. In addition, they can be processed at low temperature under mild conditions, making the device fabrication and integration much easier.

This research will enable future LED devices that are scalable and cost-effective. This project will also provide interdisciplinary training to undergraduate and graduate students, providing them with critical-thinking and problem-solving skills needed for future careers in areas of semiconductor technology.

Technical Summary

Organic-inorganic hybrid perovskites have shown tremendous potential for low-cost, energy-efficient optoelectronics (e.g. LEDs and solar cells). Development of viable devices based on the perovskites, however, has been inhibited by materials and device instability.

Among the factors that are responsible for the performance loss, ion migration appears to be intrinsic to this new class of semiconductors and remains challenging to be circumvented. This project aims to identify new ways to stabilize perovskite-LEDs by interfacial engineering. Three questions that are critical to the success of the proposed research will be answered: (1) which interface in perovskite devices is more vulnerable to ion migration? (2) could the ion migration be suppressed by introducing “extrinsic” interlayers at the grain boundary and interface? (3) what are the suitable techniques for implementing such interlayers?

Leveraging comprehensive expertise on materials chemistry and device physics, the collaborative team will unravel fundamental roles of the interfaces in materials degradation and provide a practical strategy for stabilizing perovskite devices. The ultimate goal of the project is to break the current ceiling of device stability and demonstrate perovskite-LEDs with > 1000-hour operation lifetime.

On a broader scope, the approach of interfacial engineering established in this project will also be applicable to other perovskite devices such as solar cells and photodetectors, which share many common features with perovskite-LEDs from materials selection to device architecture.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.