Description
Electric field induced second harmonic generation (EFISHG) is a powerful technique for investigating symmetry breaking in materials since it exclusively occurs in non-centrosymmetric media$^1$. This makes it a useful tool for probing charges at semiconductor interfaces, for example at silicon/dielectric boundaries$^2$ and in 2D materials$^3$. Similarly EFISHG is also effective at detecting anisotropy induced by strain or by the twisting of stacked 2D material layers$^3$.
We have demonstrated use of EFISHG to characterise charge in silicon passivating layers including samples with conductive tin oxide layers, which are incompatible with the typical method of corona oxide characterisation.
Here, we expand upon two extensions to this technique namely wavelength dependence, and time dependence (pump – probe). The former will allow for investigation of on and off resonance SHG, whilst the latter will enable investigation of carrier dynamics, i.e. from photogenerated charges.
Utilising these capabilities, we aim to extend our study to 2D material/organic heterostructures with the goal of characterising charge transfer and interlayer exciton formation within the structure.
References: 110.29026/oea.2026.250193, 210.1103/PhysRevB.35.1129, 310.1364/OME.9.001136
| I am the presenting author | Yes |
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