A Broadband CMOS Image Sensor Enabled by Monolithic 2D/3D Heterogeneous Integration

Si CMOS image sensors (CIS) dominate modern imaging technologies but are fundamentally limited to wavelengths below 1 µm by the Si bandgap. Extending CMOS imagers into the short‐wave infrared (SWIR) typically relies on hybrid integration of non‐Si photodetectors, resulting in increased fabrication complexity and cost. Here we report a broadband CMOS image sensor enabled by a monolithic 2D/3D heterogeneous integration platform. This platform integrates a PtSe 2 /Si heterojunction with an atomically flat van der Waals interface into the CIS pixel through an integration process fully compatible with back‐end‐of‐line (BEOL) process. The platform extends the conventional 4‐transistor (4T) CIS pixel into the SWIR regime. The resulting detector exhibits broadband photoresponse from 400 to 1600 nm, with a peak specific detectivity of 1.4 × 10 12 Jones at 808 nm and representative SWIR detectivities of 3.2 × 10 9 and 1.2 × 10 9 Jones at 1310 and 1550 nm, respectively, with a 3 dB bandwidth of 25 kHz. Pixel‐level measurements and system‐level imaging demonstrations confirm continuous visible‐to‐SWIR operation. By combining monolithic integration, CMOS compatibility, and broadband imaging functionality within a unified architecture, this work provides a scalable pathway for extending mature Si imaging technologies beyond their intrinsic spectral limits.