SOLID-STATE IMAGING ELEMENT

• Main Authors: SHIOMI HARUNORI, TAKIZAWA SHUICHI, ENOKI OSAMU, OKABE YUTA
• Format: Patent
• Language: English; Japanese
• Published: 17.11.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION; SEMICONDUCTOR DEVICES

To provide a solid-state imaging element capable of reducing a dark current.SOLUTION: A solid-state imaging element according to an embodiment disclosed herein includes: a photoelectric conversion layer including first semiconductor nanoparticles; and a buffer layer including second semiconductor nanoparticles. A pn junction plane is formed at an interface between the photoelectric conversion layer and the buffer layer. A product of a carrier concentration and a thickness of the buffer layer is greater than a product of a carrier concentration and a minority carrier diffusion length of the photoelectric conversion layer, and a thickness of a depletion region formed in the photoelectric conversion layer is maximized.SELECTED DRAWING: Figure 1 【課題】暗電流を低減することの可能な固体撮像素子を提供する。【解決手段】本開示の一実施の形態に係る固体撮像素子は、第１の半導体ナノ粒子からなる光電変換層と、第２の半導体ナノ粒子からなるバッファ層とを備えている。光電変換層とバッファ層との界面にｐｎ接合面が形成されている。バッファ層のキャリア濃度と膜厚の積が光電変換層のキャリア濃度と少数キャリアの拡散長の積よりも大きく、光電変換層に形成される空乏領域の厚さが最大化されている。【選択図】図１