Photovoltaic device

Abstract

Provided is a photovoltaic device with an organic buffer layer for efficiency improvement. The photovoltaic device includes a first electrode and a second electrode disposed opposite to each other, a photoactive layer disposed between the first electrode and the second electrode, and a buffer layer disposed between the photoactive layer and the second electrode. The buffer layer includes a compound including an aromatic organic cation and an anion in a quantity ranging from 30 wt % to 100 wt %, more preferably 50 wt % to 100 wt % with respect to the entire weight of the buffer layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention, and many of the above and other features and advantages of the present invention, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a partial cross-sectional view illustrating a photovoltaic device in accordance with an embodiment of the present invention;

FIG. 2 is a graph showing voltage-current characteristics of organic solar batteries prepared in accordance with Examples 1 to 4 and Comparative Examples 1 to 5;

FIG. 3 is a graph showing voltage-current characteristics of organic solar batteries prepared in accordance with Example 5 and Comparative Examples 1 to 2; and

FIG. 4 is a graph showing voltage-current characteristics of organic solar batteries prepared in accordance with Examples 3 and 5 to 7, and Comparative Example 2.

Claims

1. A photovoltaic device, comprising: a first electrode;a second electrode arranged opposite to the first electrode;a photoactive layer arranged between the first electrode and the second electrode; anda buffer layer arranged between the photoactive layer and the second electrode, the buffer layer comprising a compound including an aromatic organic cation and an anion, the compound being in a quantity ranging from about 30 wt % to 100 wt % with respect to the entire weight of the buffer layer.

2. The photovoltaic device of claim 1, wherein the buffer layer further comprises an organic semiconductor material.

3. The photovoltaic device of claim 1, wherein the compound is doped with the organic semiconductor material.

4. The photovoltaic device of claim 2, wherein 100 parts by weight of the compound is doped with less than 20 parts by weight of the organic semiconductor material.

5. The photovoltaic device of claim 1, wherein the buffer layer comprises the compound in a quantity ranging from 50 wt % to 100 wt % with respect to the entire weight of the buffer layer.

6. The photovoltaic device of claim 1, wherein the aromatic organic cation is expressed as Chemical Formula 1:

7. The photovoltaic device of claim 6, wherein the aromatic organic cation is selected from the group consisting of pyronine B, pyronine Y, rhodamine 4G, rhodamine 6G, rhodamine 3GO, rhodamine B, ethyl rhodamine B, and butyl rhodamine B.

8. The photovoltaic device of claim 1, wherein the anion of the compound is one selected from the group consisting of Cl− and NO3−.

9. The photovoltaic device of claim 2, wherein the organic semiconductor material is an n-type organic semiconductor material.

10. The photovoltaic device of claim 9, wherein the organic semiconductor material is one selected from the group consisting of fullerene (C60) and materials expressed as Chemical Formulas 2 to 31:

11. The photovoltaic device of claim 1, wherein the buffer layer is equal to or thicker than 10 Å.

12. The photovoltaic device of claim 10, wherein a thickness of the buffer layer ranges from 20 Å to 100 Å.

13. The photovoltaic device of claim 1, wherein the first electrode is a transparent electrode and the second electrode is a metal electrode.