Photodetectors are key components in a variety of industrial and scientific applications, including imaging, optical communications, environmental monitoring, and biological sensing. In order to achieve enhanced device performance, various types of semiconductors have been studied as photoactive materials. Due to the outstanding intrinsic optoelectronic and electronic properties, organic-inorganic hybrid perovskites (OIHPs) have seen a tremendous attention in the research communities of optoelectronic device. In addition, recent advancements have verified that these materials have a great potential in the field of light-signal detection.
The absorption behavior of photons incident on the active layer is affected by the Beer-Lambert law or(and) micro-cavity effect, which can be modulated by controlling the thickness of the active layer. Based on these characteristics, in many studies, the thickness of active layer has been used as a key parameter to achieve various spectral response of the perovskite photodiodes (PePDs).
However, because the active layer thickness is strongly correlated with the defect density, the variation of active layer thickness occasionally affects other device performance indices, such as dark current. To solve this problem, we varied the thickness of the charge transport layer (CTL) instead of the active layer to achieve various spectral response. By controlling the CTL thickness, we
could successfully modulate the micro-cavity effect and suggested an alternative approach to achieve a targeted spectral response of the PePDs.