Towards lead-free perovskite-based thin absorbers for imagers

Introduction

In recent years, efforts from the scientific community have been focused on the development of hybrid and inorganic perovskite materials as the active layer of many optoelectronic devices such as solar cells, photodetectors, LEDs, and lasers. Perovskites exhibit excellent optical and electrical properties: ideal band gap for solar cells, high absorption coefficient and high mobilities. The tunning of their band gap, high defect tolerance of their structure, and availability of different deposition techniques are other advantages.  However, their composition (presence of lead in their structure) and chemical and/or environmental stability are still a major concern for their commercialization. Enabling the development of stable, lead-free perovskites would push forward their integration in commercial optoelectronic devices, such as state-of-the-art imagers developed in imec.

Topic

The goal of this PhD is to explore and develop lead-free perovskite thin absorbers and integrate them in imec state-of-the-art imagers.

Lead-free perovskite thin films will be developed by thermal evaporation, while different compositions will be screened to obtain the desired performance. Photodiodes will be designed, and the stack will be determined based on electrical and optical simulations. Student will learn to fabricate and characterize the devices and feedback will be used to optimize their performance. Environmental and electrical stability will be evaluated on a regular basis. Finally, thin-film stack will be integrated within imec imager platform for state-of-the-art visible imagers.

The candidate

You are a highly motivated recent graduate holding a master’s degree in nano-engineering, material science, physics, chemistry, electrical engineering, or related. You have an interest in the development and processing of thin-film semiconductors (preferably by evaporation techniques), device fabrication, and electrical and optical characterization of both films and devices. You will be expected to work safely in a cleanroom environment and acquire processing and lab skills. It is expected that you will present results regularly.  You are a team player and have good communication skills as you will work in a multidisciplinary and multicultural team spanning several imec departments. Given the international character of imec, an excellent knowledge of English is a must.