New analytic 1D pn junction diode transient photocurrent solutions following ionizing radiation and including time-dependent carrier lifetime degradation from a non-concurrent neutron pulse.

Conference · Thu Jul 01 04:00:00 EDT 2010

OSTI ID:1021132

Axness, Carl L; Keiter, Eric Richard; Kerr, Bert ^[1]

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1. New Mexico Tech, Socorro, NM

Circuit simulation codes, such as SPICE, are invaluable in the development and design of electronic circuits in radiation environments. These codes are often employed to study the effect of many thousands of devices under transient current conditions. Device-scale simulation codes are commonly used in the design of individual semiconductor components, but computational requirements limit their use to small-scale circuits. Analytic solutions to the ambipolar diffusion equation, an approximation to the carrier transport equations, may be used to characterize the transient currents at nodes within a circuit simulator. We present new analytic transient excess carrier density and photocurrent solutions to the ambipolar diffusion equation for 1-D abrupt-junction pn diodes. These solutions incorporate low-level radiation pulses and take into account a finite device geometry, ohmic fields outside the depleted region, and an arbitrary change in the carrier lifetime due to neutron irradiation or other effects. The solutions are specifically evaluated for the case of an abrupt change in the carrier lifetime during or after, a step, square, or piecewise linear radiation pulse. Noting slow convergence of the Fourier series solutions for some parameters sets, we evaluate portions of the solutions using closed-form formulas, which result in a two order of magnitude increase in computational efficiency.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1021132
• Report Number(s): SAND2010-4579C
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMBIPOLAR DIFFUSION
APPROXIMATIONS
CARRIER DENSITY
CARRIER LIFETIME
CONVERGENCE
DESIGN
EFFICIENCY
ELECTRONIC CIRCUITS
GEOMETRY
IONIZING RADIATIONS
IRRADIATION
JUNCTION DIODES
NEUTRONS
PHOTOCURRENTS
RADIATION EFFECTS
RADIATIONS
SIMULATION
TRANSIENTS
TRANSPORT