Fundamentals of perovskite light-emitting devices pumped to high injection levels and lasing
The device physics of perovskite light-emitting diodes is far from established in the current state of the art. There are gaps in the understanding and the description of fundamental processes in the semiconductors themselves (like carrier lifetime, traps, charge transport, role of mobile ions), in particular also because there are many classes of perovskite semiconductors, and each have their own particularities (e.g. mixed organic/inorganic versus fully inorganic, quasi-2D versus 3D versus quantum dots, etc...). Furthermore, when moving from a layer of semiconductor to a heterojunction device, the hetero-interface with transport and injection layers needs to be accounted for, and also that is poorly understood today. Despite these gaps, the advances in the performance of light-emitting diodes with perovskite semiconductors are impressive, and hopes are high that injection lasing will be possible with such structures. In this PhD we will advance the fundamental understanding, thereby improving fundamental parameters of perovskite LEDs that are important for lasing, which is mainly the operation at high excitation: increase the maximum achievable current density, increase the level of electrical pumping towards population inversion, increase the brightness. From that understanding, specific device architectures will be designed, which are optimized for high current densities (with scaled-down active layers), photonic waveguiding and low optical losses. These structures will lead to injection lasing.