Optimizing perovskite thin-film system for high level of current injection

Metal halide perovskites have emerged as a promising material system for lasing applications, due to their unique properties such as high optical gain coefficients, near unity photoluminescence quantum yield and low stimulated emission threshold. To date, optically pumped lasing from a large library of optical resonators with perovskites as the gain medium has been established, both in the pulsed and continuous-wave operation modes. Recently, electrically assisted gain has been demonstrated in transparent perovskite light-emitting diodes (PeLEDs), serving as an intermediate step towards an electrically pumped perovskite laser. Many cost-effective photonic applications, such as lab-on-a-chip, would be realized thanks to an electrically pumped perovskite laser.

However, the realization of a perovskite laser diode remains elusive, due to the dual demanding requirements of optical (low stimulated emission threshold) and electrical (high quantum efficiency at kA/cm2, which is more relevant to achieve electrically pumped perovskite lasers) performance. One critical challenge when operating the PeLEDs at such high current density is the excessive Joule heating, resulting in the degradation of the quantum efficiency of  PeLEDs with increasing level of current injection. While there are many perovskite thin-film systems optimized for low current density operation (i.e. up to few of A/cm2), there is not much work done to improve the device performance at kA/cm2.
In this work, we will use the spin-coating technique to fabricate PeLEDs, which include a stack of metal halide perovskite and charge transport layers. We will then characterize the device performance under pulsed optical and/or electrical excitation. We aim to investigate the impact of fabrication parameters on the device performance, which would translate into optimization strategies to enhance the quantum efficiency at kA/cm2 range.

You will be embedded in a growing team with a healthy mix of experience levels. At all stages of the work, you can rely on the support of our highly skilled team of senior engineers and scientists. You are in your master study with a degree in nanoscience and nanotechnology, material science, chemistry, or related fields. You are highly motivated to dive with us into the world of thin film optoelectronic devices. You are a hands-on person in a lab environment and have creativity that helps you in problem solving and data analysis. It’s a plus if you have experience in working with chemicals. You are a team player and have good communication skills as you will work in a multidisciplinary and multicultural team. You have the chance to regularly present your results thus getting guidance and feedback from our team. Given the international character of imec, an excellent knowledge of English is a must.

Type of Project: Combination of internship and thesis; Thesis; Internship

Master's degree: Master of Science; Master of Engineering Science

Master program: Electrotechnics/Electrical Engineering; Materials Engineering; Nanoscience & Nanotechnology; Physics

Duration: 6 Months

Supervisor: Jan Genoe (EE, Nano)

For more information or application, please contact the supervising scientists Robert Gehlhaar (Robert.Gehlhaar@imec.be) and Karim Elkhouly (Karim.Elkhouly@imec.be). 

Imec allowance will be provided for students studying at a non-Belgian university.