Shockley-Read-Hall recombination in P3HT:PCBM solar cells as observed under ultralow light intensities

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3549820· OSTI ID:21538181

Tzabari, Lior; Tessler, Nir ^[1]

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1. Microelectronic and Nanoelectronic Centers, Electrical Engineering Department, Technion Israel Institute of Technology, Haifa 32000 (Israel)

We present light intensity dependent measurements of the quantum efficiency of P3HT:PCBM photovoltaic devices. Unlike previous studies we focus on ultralow light intensities down to 10{sup -3} mW/cm{sup 2}. We find that although when the devices are excited at intensities close to 1 Sun they exhibit very little bias or light intensity dependence, this is clearly not the case for light intensities below 1 mW/cm{sup 2}, where the cell's efficiency becomes highly dependent on the bias and light intensity. Using a simple model for the device efficiency we can fit the experimental data across a wide range of parameters and thus separate the effects of generation efficiency (geminate recombination) and charge recombination. Our finding suggests that recombination through trap (charge transfer) states is an important loss mechanism and we are able to quantify the density and depth of these states.

• OSTI ID: 21538181
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 6; Other Information: DOI: 10.1063/1.3549820; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHARGE EXCHANGE
DENSITY
INTERACTIONS
LOSSES
MASS SPECTROSCOPY
PHOTOVOLTAIC EFFECT
POLYMERS
QUANTUM EFFICIENCY
RECOMBINATION
SEMICONDUCTOR MATERIALS
SOLAR CELLS
STABILITY
TRAPS
DIRECT ENERGY CONVERTERS
EFFICIENCY
EQUIPMENT
MATERIALS
PHOTOELECTRIC CELLS
PHOTOELECTRIC EFFECT
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
SPECTROSCOPY