2, CNST @Polimi, Istituto Italiano di Tecnologia, Milan, , Italy
3, Electronic Devices, RWTH Aachen University, Aachen, , Germany
We demonstrate latest achievements of integrated perovskite devices on a silicon nitride photonic platform. Perovskite as a class of solution processed semiconductors with a direct bandgap offering a variety of interesting emission wavelengths for on-chip photonics. Spin-coating enables a possibility of direct integration of the lasing material as a counterpart to epitaxial growth with is not applicable on amorphous substrates such as silicon nitride.
We report on methylammonium lead iodide (MAPbI3) perovskite micro-disc and microring lasers which are monolithically integrated into silicon nitride photonic integrated circuits showing low lasing thresholds at room temperature. The perovskite micro-discs are placed in the vicinity of a single mode silicon nitride waveguides so that the generated laser light can be directly used by a photonic circuitry.
A top-down lithographic structuring approach has been developed to pattern perovskite micro-discs without degenerating the active material. This method paves the way to more complicated circuits and structures enabling electrically pumped perovskite laser in the near future. High-throughput fabrication techniques can be applied enabling the usage of the material in commercial systems; i.e. optoelectronic circuits with monolithically integrated lasers. We report on fabrication technologies for reproducible on-chip devices with low device-to-device variations and low sample-to-sample variation with almost 100 measured devices. The lasing thresholds are in the order of 5 µJcm-2 which outperforms most unpatterned single crystal perovskite lasing demonstrations. The laser emission lies at ~785 nm and is narrow in linewidth (~1 nm). The micro-discs were optically pumped at room temperature in ambient conditions with 120 fs laser pulses with 250 kHz repetition rate at 630 nm wavelength. X-ray diffraction crystallography has been performed prior to processing the perovskite and on the final device showing only small changes in the material after the patterning process. Device performance is confirmed by simulations (Finite Difference Time Domain, FDTD).
Our fabrication approach is fully reproducible and is a technological base for mass-fabrication of active optoelectronic circuits with hybrid perovskite-dielectric waveguide materials.