# US 2013/0154040 A1 · Photo detectors

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- Number: US 2013/0154040 A1
- Document ID: US20130154040A1
- Status: Published application
- Kind: A1
- Application number: 13/612,760
- Filed: 2012-09-12
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Electronics and Telecommunications Research Institute
- Inventors: Chul Huh; Sang Hyeob Kim; Byoung-Jun Park; Eun Hye Jang
- Web page: https://patentgrep.com/patent/US20130154040A1

## CPC

- H10F 77/407: {indirectly associated with the devices}
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- H10F 30/22: the devices having only one potential barrier, e.g. photodiodes
- H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

Photo detectors are provided. The photo detector includes a photoelectric conversion layer between a lower carrier transportation layer and an upper carrier transportation layer, and a common electrode on the upper carrier transportation layer opposite to the photoelectric conversion layer. The photoelectric conversion layer includes a plurality of light absorption layers and each of the light absorption layers contains silicon nanocrystals. The silicon nanocrystals in respective ones of the light absorption layers have different sizes from each other.

## Claims

### Claim 1

A photo detector comprising:
a photoelectric conversion layer between a lower carrier transportation layer and an upper carrier transportation layer; and
a common electrode on the upper carrier transportation layer opposite to the photoelectric conversion layer,
wherein the photoelectric conversion layer includes a plurality of light absorption layers and each of the light absorption layers contains silicon nanocrystals; and
wherein the silicon nanocrystals in respective ones of the light absorption layers have different sizes from each other.

### Claim 2 (depends on 1)

The photo detector of claim 1, wherein a size of the silicon nanocrystals in each light absorption layer is gradually increased as the light absorption layer becomes closer to the common electrode.

### Claim 3 (depends on 1)

The photo detector of claim 1, wherein each of the light absorption layers include a silicon nitride layer containing the silicon nanocrystals.

### Claim 4 (depends on 1)

The photo detector of claim 1, further comprising a metal particle layer between the upper carrier transportation layer and the common electrode,
wherein the metal particle layer includes metal particles having a size of about a few nanometers to about several hundreds of nanometers.

### Claim 5 (depends on 4)

The photo detector of claim 4, wherein the metal particle layer includes at least one species of gold particles, silver particles and aluminum particles.

### Claim 6 (depends on 1)

The photo detector of claim 1, wherein the lower carrier transportation layer includes a semiconductor material doped with impurities of a first conductivity type.

### Claim 7 (depends on 6)

The photo detector of claim 6, wherein the upper carrier transportation layer includes a semiconductor material doped with impurities of a second conductivity type opposite to the first conductivity type.

### Claim 8 (depends on 1)

The photo detector of claim 1, wherein the upper carrier transportation layer includes a silicon carbide type material.

### Claim 9 (depends on 1)

The photo detector of claim 1, wherein the common electrode is a conductive electrode including indium tin oxide (ITO), SnO2, In2O3, Cd2SnO4 or ZnO.

### Claim 10 (depends on 1)

The photo detector of claim 1, further comprising:
an upper electrode on the common electrode; and
a lower electrode under the lower carrier transportation layer,
wherein each of the upper and lower electrodes includes nickel or gold.

### Claim 11

A photo detector comprising:
a first light absorption layer, a second light absorption layer and a third light absorption layer sequentially stacked on a lower carrier transportation layer; and
an upper carrier transportation layer on the third light absorption layer,
wherein the first light absorption layer includes first nanocrystals having a first size, the second light absorption layer includes second nanocrystals having a second size greater than the first size, and the third light absorption layer includes third nanocrystals having a third size greater than the second size.

### Claim 12 (depends on 11)

The photo detector of claim 11, wherein incident lights are irradiated onto a top surface of the upper carrier transportation layer opposite to the third light absorption layer.

### Claim 13 (depends on 11)

The photo detector of claim 11, wherein each of the first to third light absorption layers includes a silicon nitride layer.

### Claim 14 (depends on 11)

The photo detector of claim 11, wherein the first to third nanocrystals are silicon nanocrystals.