Optimized Tamm-plasmon structure by Differential Evolution algorithm for single and dual peaks hot-electron photodetection

Wavelength-selective photodetectors with dual and multiple narrowband spectral responses in the infrared range are essential in the development of hyperspectral imaging technology and have attracted great attention due to their potential applications in a variety of areas such as resource remote sensing and mineral exploration. Here, we introduce an efficient optimization of Tamm-plasmon (TP) structure-based hot electron photodetection devices in the telecommunications wavelengths. The devices consist of a Si/SiO2 distributed Bragg reflector (DBR) multilayer structure atop of an Au/n-Si Schottky diode. The DBR structure is optimized using Differential Evolution (DE) algorithm for wavelength-selectivity and ultra-narrow linewidths at arbitrarily wavelengths. DE shows excellent capability and efficiency in solving a high dimensional continuous optimization problem with competitive speed. The optimized TP structure by DE exhibits near-unity absorptance at the designed wavelengths and requires a relatively short computation time on a standard computer of approximately one and three days to search the optimized TP structures for single and dual absorption peak photodetection, respectively. This result shows that DE is efficient for multilayer structure optimization. Finally, a mechanism for selective photodetection of the two sensitive wavelengths is proposed by tuning the height of the Au/n-Si Schottky barrier with a bias voltage. This wavelength selection mechanism opens the way for dual absorption peaks photodetection.