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Quantum Efficiency in Perovskite Light Emitting Diodes under Low to High Current Densities
Penn State interdisciplinary Materials (2017)
  • Mike Lopez, University of Central Florida
Next generation technology is reliant on discovering innovative ways to produce substantial amounts of versatile materials.  As for light emitting diodes (L.E.D), they have attracted much attention in research and industry thanks to their versatility and efficiency.  Recently scientist have been able to use organic semiconductor materials to fabricate LEDs.  In the past decade, the application use of these devices skyrocketed by making up most of our phone displays and televisions today.  However, unfortunately every LED is limited by their efficiency as they reach higher levels of brightness.  This plague is known as an effect called roll-off.  Recently, scientists have been studying why this roll off occurs and what we can do to prevent it.
In this project, I have explored the efficiency roll-off of a perovskite LED at high current densities.  External quantum efficiency (EQE) of microscale devices has been measured under short voltage pulses to eliminate device heating so that I can uncover the fundamental causes of efficiency roll-off at much higher current densities that have been tested to date.  The challenges included in this project are the device’s lifetime and the method used to measure photocurrent.  Consequently, each device is susceptible to failure if given enough current.  Even though we send pulsed signals through the device that does not necessarily prevent the device from overheating.  That is why, it is imperative to use caution when performing measurements.  Moreover, due to micron scale device sizes, we came up with the configuration that uses a camera with electron multiplication charged coupled device to capture the photons emitted.
  • Light Emitting Diode,
  • Perovskite
Publication Date
Summer July 28, 2017
Citation Information
Mike Lopez. "Quantum Efficiency in Perovskite Light Emitting Diodes under Low to High Current Densities" Penn State interdisciplinary Materials (2017)
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