Sony’s latest smartphone camera sensor collects twice as much light

Sony has discovered a new type of stacked CMOS sensor that uses “dual-layer transistor pixels” to double the ability to collect light. Typical image sensors have light-sensitive photodiodes and pixel transistors that control and amplify the signal on the same layer. However, the new design puts photodiodes at the top and pixel transistors at the bottom, “roughly doubling the saturation signal levels,” Sony said.

Sony was a pioneer stacked sensors which places fast memory and other electronics directly under the sensor, which allows higher read speeds, and thus fast burst shooting and reduced rotation (jello effect) on cameras and smartphones. This latest sensor uses a similar idea, but packs the pixel transistors on a separate substrate under the photodiode layer.

This means that each layer could be optimized, allowing Sony to double the saturation of the sensor light (well depth), or the amount of charge that each pixel can retain. This in turn allows for about twice the ability to capture light.

Sony notes that since the transistor’s pixels are on a separate layer, it has managed to increase the size of the amplifier’s transistors. This allows for higher signal amplification, reducing noise when shooting night or other images in dark places. The increased dynamic range will enable “high-quality, low-noise images even in low light,” according to Sony.

Sony specifically stated that the technology will enable better quality photography of the smartphone. With twice the ability to collect light, it will provide significantly improved sensitivity to light even with relatively small sensors with high megapixels. Sony has not yet said when this technology will reach smartphones or cameras, but plans to further improve the design for large and small sensors.