The excellent performance of bolometers in the infrared and terahertz regions has attracted great attention. Understanding the transport process of charged particles is an efficient approach to determine detector performance. However, the lack of studies on the fine‐scale spatial motion of microscopic particles in bolometers has prevented a full understanding of the physical process. Herein, using micro‐nano‐scale optoelectronic performance correlation measurements, it is described how prevalent defect states at the grain boundaries (GBs) decrease current responses. Ions at the GBs of the polycrystalline perovskite bolometer contribute to the photocurrent via thermal excitons. In addition, the built‐in electric field established by ion migration fluctuates periodically with the strength of the light‐heating process due to the interaction between the bolometric effect and the Coulomb force. Additionally, the first ion‐bolometric detector is demonstrated with a significant photovoltage response to infrared and THz waves (75.3 kV W−1 at 1064 nm and 2.3 kV W−1 at 0.22 THz). An examination of the THz images shows the potential for large‐area THz imaging applications. The ion‐bolometric effect combines the broad spectral characteristics of the bolometer effect with the temperature sensitivity due to ion migration and provides a unique perspective on detector technology.

Controlling and directing colloidal micro/nanoparticle assembly using external forces is essential to developing modern electro-optical devices. Here we show that the concentration gradients of metal ions produced by chemical/electrochemical corrosion could drive the motion of colloidal microspheres under the assistance of a well-known osmotic force. This force is programmable in both direction and strength which enables us to guide the moving directions of microspheres at controlled rates. To demonstrate the utility of this force in producing ordered assemblies, dynamic colloidal “crystals” built with one and/or two types of microspheres that replicate the electrode templating patterns are created. In addition, the motion of particles and their dynamic assembly are reproduced by a simulation combining Poisson–Nernst–Planck and Navier–Stokes equations. We believe this method opens the door to the development of complex patterns (e.g., differing in pattern shapes, homo- and/or heterojunctions with two or multiple components) self-assembled by colloidal particles and functional materials with electro-optical properties.