2024/09/17 by Andreas Salomon, Salomon, Andreas, Johannes Aberl +19
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optics (physics.optics) #Semiconductor Quantum Structures and Devices #Silicon Nanostructures and Photoluminescence #Thin-Film Transistor Technologies
paper · pdf · doi:10.48550/arxiv.2409.11081
openalex publication_date 2024/09/17 · openalex created_date 2024/10/24 · openalex updated_date 2026/08/01
The lack of straightforward epitaxial integration of useful telecom lasers on silicon remains the major bottleneck for bringing optical interconnect technology down to the on-chip level. Crystalline silicon itself, an indirect semiconductor, is a poor light emitter. Here, we identify conceptionally simple Si/Si1-xGex/Si double heterostructures (DHS) with large Ge content (x \gtrsim 0.4) as auspicious gain material suitable for Si-based integrated optics. In particular, using self-consistent Poisson-current transport calculations, we show that Si diodes containing a 16 nm thick Si1-xGex layer of high crystalline quality, centered at the p-n junction, results in efficient carrier accumulation in the DHS and gain if the diode is driven in forward direction. Despite the high strain, we unambiguously demonstrate that such prior unattainable defect-free DHS can be fabricated using ultra-low temperature epitaxy at pristine growth pressures. Telecom light emission is persistent up to 360 K, and directly linked to a ~160 meV high conduction band barrier for minority electron injection. This epitaxy approach allows further increasing the Ge content in the DHS and creating dot-in-well heterostructures for which even higher gains are predicted. Thus, the surprisingly facile DHS presented here can be an essential step toward novel classes of group-IV optoelectronic devices for silicon photonics.