This timeline displays the progress made in the area of photovoltaic cells, particularly in the area of organic-based solar cells (Plastic solar cells). The time line starts with Becquerel's observation of the photoelectric effect. For each event of the timeline, click the arrow button to read more about that event.

This time line was created by Mr. Andrew Blair and Prof. D. Venkataraman at the University of Massachusetts Amherst. Andrew is a freshman and participated in the First Year Research Experience Program. We thank Prof. Steve Goodwin, Dean of the College of Natural Sciences and Prof. Julian Tyson, Associate Dean of the College of Natural Sciences at UMass Amherst for their support.;xNLx;;xNLx;Email your questions or comments to dv'at'

1839-09-29 00:00:00

Becquerel's observation

Becquerel observed a photocurrent between two electrodes submerged in solution, the photoelectrochemical process. A. E. Becquerel a.k.a. Edmund Becquerel, was the father of Henri Becquerel, who discovered Radioactivity

1873-02-20 00:00:00

Willoughby Smith observes photoconductivity in Selenium

Willoughby Smith observes photoconducivity in selenium.

1883-02-01 00:00:00

Charles Fritts Purportedly Builds Selenium Solar Cell

Charles Fritts builds on Willoughby Smith's observation and fabricates a Se Cell. Most sources refer to American Journal of Science 1883, 26, 465. We are unable to find this reference or verify this claim.

1888-09-29 00:00:00

First Photoelectric Cell is Built

Aleksandr Stoletov builds the first photoelectric cell based on the photoelectric effect.

1906-03-11 01:11:36

Study of anthracene

Pochettino studied the photoconductivity of anthracene.

1921-09-28 19:21:07

Einstein's Nobel prize

Albert Einstein receives the Nobel Prize for "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect"

1954-08-13 08:42:08

Bell develops solar cell

Bell Laboratories develops the first inorganic solar cell based on silicon. Three years later, US Patent Office issues a patent to Bell Labs for 'Solar Energy Converting Apparatus' (2,780,765).

1958-08-13 08:42:08

Kearns/Calvin Created Bilayered Device

David Kearns and Melvin Calvin create a 'bilayered device' using magnesium phthalocyanine and oxidized tetramethyl p-phenylenediamine. This device created 200mV with a power output of 3 x 10^-12 W.

1961-09-29 00:00:00

Shockley-Queissier Limit

The "detailed balance limit of efficiency," also known as the Shockley-Queissier limit, is established, giving bounds to the achievable efficiencies of photovoltaics.

1974-09-29 20:01:43

Use of Ohmic Contacts in OPV Device Architecture

P.H.Fang devises equation to convert between apparent efficiency and real efficiency, leading to the idea of improvement of efficiency by Ohmic contact with organic materials.

1976-09-29 20:01:43

Hydroxy squarylium dye

Merritt and Hovel make films of OHSq, or hydroxy squarylium, dye which absorb light nearly encompassing the entire visible light spectrum. Also, .2% efficiency in Ga- and Hg-topped films.

1977-09-29 00:00:00

GaAlAs/GaAs Cells

R. D. Dupuis et al. create 12.8% (uncorrected) efficiency GaAlAs/GaAs cells grown through chemical vapor deposition, employing metalorganic and hydride sources. This was the first successful growth of these structures.

1977-09-29 00:00:00

NREL begins operation as SERI

On Jul 5, 1977, NREL began its operation as SERI, the Solar Energy Research Institute.

1978-09-29 17:31:39

Merocyanine Organic Cells

Ghosh and Feng develop a theoretical model explaining the observed efficiency in .7% merocyanine organic solar cells. Click "Find out more" to read their abstract.

1978-09-29 20:01:43

OPV breaks the 1% Barrier

Researchers from Exxon Mobil report an OPV device with 1% efficiency (corrected) using semi-transparent aluminum electrodes. Prior progress had only achieved approximately .02% sunlight efficiency.

1986-09-29 17:31:39

Two-layer organic photovoltaic cell

Tang from Eastman Kodak creates the first two-layer organic thin film, in which a single layer of organic material is sandwiched between two dissimilar electrodes. This first two-layer cell had a .95% power conversion efficiency, which, at that time, was one of the highest reported efficiencies.

1991-09-29 07:31:05

Gratzel Reports Dye-sensitized TiO2 Cell

O'Regan and Gratzel report the now famous 'Gratzel solar cell' using dye-sensitized colloidal TiO2 films.

1991-09-29 17:31:39

First dye/dye bulk heterojunction PV is made

Scientists from Osaka University make the first dye/dye bulk heterojunction PV by co-sublimation. The cell had an efficiency of 0.7%

1993-09-29 22:43:42

Fullerene used as Electron Acceptor

Scientists from UC Santa Barbara report photoinduced electron transfer from MEH-PPV to C60.

1994-09-29 22:43:42

Polymer Photovoltaic Cells are Here

Scientists from UC Santa Barabara report solar cells based on MEH-PPV and C60.

1995-09-29 07:31:54

All Polymer Active Layer Solar Cells Explored

All polymer photodiodes reported by independently by Heeger and Friend Groups.

2000-09-29 07:31:54

Oligomer-Fullerene Dyads as Active Material

Scientists from Eindhoven report the use oligomer-carbon-60 dyads/triads as active material in PV cells.

2000-09-29 07:31:54

Improvements in Gratzel Cell

A. Hagfeldt and Gratzel propose TiO2 nanoparticle film structure for ultrafast charge separation and increased efficiency.

2001-09-29 00:00:00


Konarka opens in July of 2001, marking the beginning of the innovative manufacture of plastic solar cells.

2001-09-29 07:31:54

Plastic Solar Cells

C.J. Brabec et al. use plastics and increase the power conversion efficiency to 3%. Buckminsterfullerene is also used for ultrafast electron transfer. The recent improvements in efficiency enhanced emphasis in the field from multiple groups worldwide.

2001-09-29 07:31:54

Liquid crystalline solar cell

L. Schmidt-Mende et al. report a self-organized liquid crystalline solar cell composed of hexabenzocoronene and perylene.The efficiency was 1.95% at 495 nm.

2001-09-29 07:31:54

Double-cable polymers in PV

Ramos uses double-cable polymers in photovoltaic cells.

2002-03-29 07:31:05

Hybrid Nanorod-Polymer Solar Cells

Paul Alivisatos and co-workers report P3HT-CdSe Nanoparticle device with PCE of 1.7%.

2005-09-29 07:31:05

High Efficiency cells

G. Li et al. create 5% power conversion efficiency polymer photovoltaics using polymer blend of poly(3-hexylthiophene) and methanofullerene.

2005-09-29 07:31:05

Stable All Nanocrystal Cells

I. Gur et al. synthesize ambient-environment-stable, ultrathin all inorganic nanocrystal solar cells.

2009-08-13 08:42:08

EFRC is born

U.S. Department of Energy’s Office of Science established 46 Energy Frontier Research Centers (EFRCs) to accelerate research toward meeting critical energy challenges.

2009-09-16 21:55:23

All-polymer solar cell

Holcombe et al. of U.C. Berkeley synthesize an all-polymer solar cell form Grignard Metathesis polymerization

2010-01-04 07:31:05

Luping Yu reports PTB7 with 7.4% efficiency OPV

Y. Liang et al. create prototype polymer organic photovoltaic cells with PTB7. The OPV cells show power conversion efficiencies of 7.4%

2011-09-29 00:00:00

9.2% efficiency OPV

Mitsubishi Chemical announces the production of 9.2% PCE OPV.

2012-06-16 21:55:23

Solution-processed OPV of 7% PCE

van der Poll et al. produce high-efficiency small-molecule OPV

2012-09-29 00:00:00

10.7% Efficiency OPV

Heliatek announces the prototype 10.7% PCE OPV

2012-09-29 00:00:00

Konarka files for bankruptcy

Konarka files for Chapter 7 Bankruptcy Protection, marking "a tragedy for...the development of alternative energy in the United States."

2012-09-29 00:00:00

NREL Chart

The most recent NREL chart for PV efficiencies

2012-10-31 00:00:00

All-Carbon solar cell

Ramuz et al. produce the first all-carbon solar cell.

2012-11-02 00:00:00

Use of Organometal Halide Perovskites

The use of organometal halide pervoskites as light absorbers results in 10.9% efficency by Snaith and co-workers

2013-01-18 00:00:00

Heliatek Announces 12% Efficiency

Heliatek announced that they are able to make an organic solar cells (with small molecules) with 12% efficiency.

2013-06-03 00:00:00

10.2% PCE in a tandem cell with two identical sub-units

Yang Yang's group report a 10.2% PCE in a tandem cell with two identical subunits.

2013-08-11 00:00:00

High Fill Factors and Packing

Marks and co-workers achieve upto 80% FF in OPVs.


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