Photosensitive device
A photosensitive device is provided. The photosensitive device includes a sensing stack, an anti-reflective layer, an optical filter, a first electrode, and a second electrode. The sensing stack includes a first semiconductor layer, an intrinsic semiconductor layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the intrinsic semiconductor layer. The anti-reflective layer is disposed on a side of the sensing stack. The optical filter is disposed on the anti-reflective layer and blocks input light with an incident angle greater than 50 degrees. The first electrode and the second electrode are disposed on the sensing stack.
1 . A photosensitive device, comprising:
a sensing stack comprising:
a first semiconductor layer;
an intrinsic semiconductor layer disposed on the first semiconductor layer; and
a second semiconductor layer disposed on the intrinsic semiconductor layer;
an optical filter disposed on a side of the sensing stack and comprising high refractive films and low refractive films alternately stacked, wherein the optical filter blocks any input light having an incident angle greater than 50 degrees;
an anti-reflective layer disposed between the sensing stack and the optical filter; and
a first electrode and a second electrode connected to the sensing stack;
wherein the total number of the high refractive films and the low refractive films is thirteen or more than thirteen.
2 . The photosensitive device as claimed in claim 1 , wherein a refractive index of the high refractive films and low refractive films is from 1.3 to 2.5.
3 . The photosensitive device as claimed in claim 2 , wherein the refractive index of the high refractive films is from 2.0 to 2.5 and the refractive index of the low refractive films is from 1.3 to 1.5.
4 . The photosensitive device as claimed in claim 1 , wherein a thickness of the optical filter is from 1500 nm to 1950 nm.
5 . The photosensitive device as claimed in claim 1 , wherein the optical filter comprises a metal element.
6 . The photosensitive device as claimed in claim 5 , wherein the metal element comprises sodium, niobium, titanium, silver, barium, or a combination thereof.
7 . The photosensitive device as claimed in claim 1 , wherein a material of the anti-reflective layer comprises silicon nitride.
8 . The photosensitive device as claimed in claim 1 , wherein a thickness of the anti-reflective layer is from 50 nm to 100 nm.
9 . The photosensitive device as claimed in claim 1 , wherein the first electrode and the second electrode are both on the same side of the first semiconductor layer opposite the intrinsic semiconductor layer.
10 . The photosensitive device as claimed in claim 1 , wherein the first electrode is disposed on the first semiconductor layer, and the second electrode is disposed under the second semiconductor layer.
11 . The photosensitive device as claimed in claim 10 , further comprising a dielectric ring disposed on the intrinsic semiconductor layer and surrounding the second semiconductor layer.
12 . The photosensitive device as claimed in claim 10 , wherein the dielectric ring is in direct contact with the intrinsic semiconductor layer.
13 . The photosensitive device as claimed in claim 12 , wherein the intrinsic semiconductor layer is surrounded by the first semiconductor layer.
14 . The photosensitive device as claimed in claim 10 , wherein the anti-reflective layer covers a top surface of the dielectric ring.
15 . The photosensitive device as claimed in claim 1 , wherein the anti-reflective layer is a continuous layer.
16 . The photosensitive device as claimed in claim 1 , wherein the optical filter is a continuous layer.
17 . The photosensitive device as claimed in claim 1 , wherein the optical filter comprises silicon.
18 . The photosensitive device as claimed in claim 1 , wherein the first electrode comprises a side surface covered by the anti-reflective layer.
19 . The photosensitive device as claimed in claim 1 , wherein the anti-reflective layer directly contacts the sensing stack.