In Situ Investigations and Strategies for Addressing Extrinsic and Intrinsic Degradation Mechanisms in Perovskite Solar Cell Materials and Devices.
Abstract
Abstract: High specific power solar cells, which offer inherent security features associated with quiet operation and low thermal signatures, can reduce the equipment burden for warriors, and are desired for generation of electrical power for both warrior electronics and off-grid bases. Remarkable progress has been made in perovskite solar cells in only the past few years with power conversion efficiencies now exceeding 22% and rivaling the best available terrestrial photovoltaic technologies. In fact, perovskite solar cells are now being considered as a viable alternative to other more established photovoltaic technologies such as crystalline Si, CdTe, and CuIn1–xGaxSe2. While these latter technologies have been successfully commercialized, the large-scale deployment of perovskite solar cells is hindered by performance degradation during operation. Although ?4 months of stability have recently been demonstrated in a dry environment, a significantly longer lifetime in a variety of different low and high humidity/temperature environments will be required for perovskite solar cells to be widely adopted. A long lifetime in operation and on-the-shelf will be essential for the Navy’s war-fighting and logistical missions, and the operation of any solar cell device in the field must be reliable, repeatable, and robust. If the lifetime can be improved, pathways exist for fabrication of very high power density solar cells. The work proposed here will develop the understanding to allow the stability of perovskite solar cells to be dramatically improved, and this knowledge will unlock the promise of high power density solar cells for Naval missions. Efforts at the University of Toledo will develop a detailed understanding of the degradation and hysteresis mechanisms in perovskite solar cells to allow the technology to be advanced for Naval relevance. Specifically, we will; (1) Characterize both the intrinsic and extrinsic degradation mechanisms for perovskite solar cells as a function of cell geometry, the materials used, type of construction, and environmental factors (e.g. humidity, temperature, spectral irradiance, bias); (2) Understand these behaviors from the basic principles associated with the relevant thermodynamic, kinetic, and mass transport issues and processes; and (3) Assess the potential for existing and near-term-horizon perovskite solar cells for missions critical to the Office of Naval Research, and identify and pursue next generation opportunities and solutions. Efforts will include characterization of device performance and materials/interface changes that occur under carefully controlled environments (temperature, photons, bias, ambient gas composition) for a host of different device architectures and BAA Number: N00014-17-S-B001 (Short) materials choices with a strong coupling to theory and modeling. We will utilize a host of existing capabilities and construct additional multichannel testing stages in environmental chambers for high throughput experimentation. Devices will be examined in encapsulated and un?encapsulated forms, in?house, on a variety of substrates. In addition to in situ current/voltage, quantum efficiency, X?ray diffraction, and Uv?Vis?IR optical spectroscopies and ex situ microscopies, we will also apply in situ laser beam induced current measurements and real?time spectroscopic ellipsometry with radiation from the THz to the far UV. These experiments, when coupled with density functional theory, will help develop a detailed understanding of degradation mechanisms and reveal which mechanisms are fundamental to the materials and which can be avoided. The outcomes will identify paths toward developing stable perovskite solar cells.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2017
- Source ID
- N000141712223
Entities
People
- Michael J. Heben
Organizations
- Office of Naval Research
- United States Navy
- University of Toledo