CMOS image sensor having thiophene derivatives
Provided is a CMOS image sensor that uses thiophene derivatives. The CMOS image sensor includes first through third photoelectric conversion units vertically and sequentially stacked on a semiconductor substrate. The first photoelectric conversion unit detects blue light and comprises a first electrode, a second electrode, and a p-type thiophene derivative layer between the first electrode and the second electrode.
1. A CMOS image sensor comprising first through third photoelectric conversion units sequentially formed on a semiconductor substrate, in which the first through third photoelectric FW: conversion units are vertically stacked with predetermined depths respectively, wherein
the first photoelectric conversion unit detects blue light and comprises:
a first electrode;
a second electrode; and
a p-type thiophene derivative layer between the first electrode and the second electrode,
wherein the p-type thiophene derivative layer comprises pentathiophene.
2. The CMOS image sensor of claim 1 , wherein the first photoelectric conversion unit further comprises an n-type thiophene derivative layer between the p-type thiophene derivative layer and the second electrode.
3. The CMOS image sensor of claim 2 , wherein the n-type thiophene derivative layer is formed of perfluoropentathiophene.
4. The CMOS image sensor of claim 2 , wherein the first photoelectric conversion unit further comprises an electron blocking layer between the first electrode and the p-type thiophene derivative layer.
5. The CMOS image sensor of claim 4 , wherein the electron blocking layer is formed of tri(1-phenylpyrazolato)iridium (Ir(ppz) 3 ).
6. The CMOS image sensor of claim 4 , wherein the first photoelectric conversion unit further comprises a hole blocking layer between the second electrode and the n-type thiophene derivative layer.
7. The CMOS image sensor of claim 6 , wherein the hole blocking layer is formed of bathocuproine (BCP) or 3-phenyl-4-(1′-naphthyl)-5-phenyl-1,2,4-triazole (TAZ).
8. The CMOS image sensor of claim 6 , wherein the first photoelectric conversion unit further comprises an intrinsic layer between the p-type thiophene derivative layer and the n-type thiophene derivative layer, the intrinsic layer being formed by co-depositing a p-type thiophene derivative and an n-type thiophene derivative.
9. The CMOS image sensor of claim 2 , wherein the first photoelectric conversion unit further comprises an intrinsic layer between the p-type thiophene derivative layer and the n-type thiophene derivative layer, the intrinsic layer being formed by co-depositing a p-type thiophene derivative and an n-type thiophene derivative .
10. The CMOS image sensor of claim 1 , wherein the first photoelectric conversion unit further comprises an electron blocking layer between the p-type thiophene derivative layer and the first electrode and a hole blocking layer between the p-type thiophene derivative layer and the second electrode.