| CPC H10F 39/8063 (2025.01) [G01S 7/4816 (2013.01); G01S 7/4863 (2013.01); G01S 17/894 (2020.01); G02B 3/0037 (2013.01); H10F 39/184 (2025.01); H10F 39/8057 (2025.01)] | 16 Claims |
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1. A photoelectric conversion element, comprising:
a substrate having a first surface on which reflected light reflected from an object is incident, and including a first semiconductor region and a second semiconductor region, the second semiconductor region being formed in a direction perpendicular to the first surface and extended from the first surface toward an inside of the substrate; and
an optical element positioned on a first surface side of the substrate and configured to collect the reflected light to the second semiconductor region,
wherein the first semiconductor region comprises a first conductive type semiconductor, the second semiconductor region comprises a second conductive type semiconductor whose conductive type is different from that of the first conductive type semiconductor, and
the substrate and the optical element are configured such that a relational expression 0.95*exp(−α(λ)*z)≤B(z)/A1≤1.05*exp(−α(λ)*z) is established at a distance z=z0 when A1≥A2 is satisfied and a distance z0=In(2)/α(λ) is established,
where I is incident energy of the reflected light incident on the photoelectric conversion element,
α(λ) is an absorption coefficient of the reflected light in the substrate where λ is an average wavelength of a light source,
A1 is incident energy of the reflected light in a predetermined region on the first surface,
A2 is incident energy of the reflected light in the predetermined region on the first surface in a case where the photoelectric conversion element does not include the optical element, and
B(z) is incident energy of the reflected light in a region translated from the predetermined region by a predetermined distance z in a thickness direction of the substrate.
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