Materials, systems and methods for optoelectronic devices
A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.
1. An image sensor comprising:
a semiconductor substrate;
a substantially continuous optically sensitive layer over the semiconductor substrate;
a plurality of pixel regions, each pixel region comprising a region of the optically sensitive layer over the semiconductor substrate, the optically sensitive layer separated from the semiconductor substrate on a side by at least one adjacent layer, wherein vias couple the optically sensitive layer and the semiconductor substrate; and
a pixel circuit for each pixel region, each pixel circuit comprising a charge store and a read out circuit, wherein the charge store is separate for each pixel region and wherein the read out circuit is common with the read out circuit for at least one set of other pixel regions, the read out circuits being configured such that a bias across the optically sensitive layer decreases throughout an integration period of time.
2. A photodetector comprising:
a semiconductor substrate;
a substantially continuous optically sensitive layer over the semiconductor substrate;
a plurality of pixel regions, each pixel region comprising a region of the optically sensitive layer over the semiconductor substrate, the optically sensitive layer comprising nanocrystals, the optically sensitive layer separated from the semiconductor substrate on a side by at least one adjacent layer, wherein vias couple the optically sensitive layer and the semiconductor substrate; and
a pixel circuit for each pixel region, each pixel circuit comprising a charge store and a read out circuit, wherein the charge store is separate for each pixel region and wherein the read out circuit is common with the read out circuit for at least one set of other pixel regions, the read out circuits being configured such that a bias across the optically sensitive layer decreases throughout an integration period of time.