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'

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

First Photoelectric Cell is Built

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

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"

Study of anthracene

Pochettino studied the photoconductivity of anthracene.

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).

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.

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.

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.

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.

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.

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