NIEL Dose Analysis on triple and single junction InGaP/GaAs/Ge solar cells irradiated with electrons, protons and neutrons

Abstract

Triple junction (InGaP/GaAs/Ge) and single junction (SJ) solar cells were irradiated with electrons, protons and neutrons. The degradation of remaining factors was analyzed as function of the induced Displacement Damage Dose (DDD) calculated by means of the SR-NIEL (Screened Relativistic Non Ionizing Energy Loss) approach. In particular, the aim of this work is to analyze the variation of the solar cells remaining factors due to neutron irradiation with respect to those previously obtained with electrons and protons. The current analysis confirms that the degradation of the P max electrical parameter is related by means of the usual semiempirical expression to the displacement dose, independently of type of the incoming particle. I sc and V oc parameters were also measured as a function of the displacement damage dose. Furthermore, a DLTS analysis was carried out on diodes -with the same epitaxial structure as the middle sub-cell -irradiated with neutrons.

Particle‐induced degradation of III–V multi‐junction solar cells under different configurations of displacement damage dose

“…In Campesato et al, [ 8 ] it was shown the T d value allowing best fit of experimental DDD data was 24 and 21 eV for 3J cell and middle GaAs cell, respectively. Despite the middle GaAs cell is considered to be mainly responsible for the degradation, the actual 3J structure (with top and bottom sub‐junctions) adds to the complexity in the degradation mechanisms, and contribution to the global response is not limited to GaAs sub‐layer alone.…”

Proton‐Radiation Tolerant All‐Perovskite Multijunction Solar Cells

“…In the case of the III–V 3J on Ge, we identify significant degradation specifically within the GaAs middle cell, which is in line with literature reports of III–V on Ge space PV under high energy irradiation. [ 47,48 ] The spectral response of the InGaP and Ge subcell are barely affected, but in the latter case, we notice a reduction of the indirect gap ( E indirect.gap (Ge) = 0.62 eV) [ 49 ] absorption features with increasing proton dose, while above the direct gap of Ge ( E direct.gap (Ge) = 0.81 eV) [ 49 ] the spectral response increases again to its initial value. Due to the low intensity of the solar spectrum in that region, this has little to no effect on the integrated current but nevertheless points towards some radiation‐induced changes in the Ge subcell that, to our knowledge, has not been described yet.…”

Comparison of 10 MeV Neutron Irradiation Effects on NiO/Ga2O3 Heterojunction Rectifiers and Ni/Au/Ga2O3 Schottky Rectifiers

“…There are numerous applications where neutron exposure to neutron fluxes may occur, including nuclear reactors or simply terrestrial neutron showers due to interactions of high-energy primary cosmic rays with gases in the upper atmosphere. 36,37 This flux increases at lower altitude due to a higher number of cosmic ray-gas and neutron-gas interactions, The maximum flux is ∼1 n cm −2 s at 20 km altitude. The terrestrial neutron flux decreases at lower altitudes altitude due to scattering and decreased cosmic ray energy.…”

“…One of the most common forms of radiation encountered by semiconductor devices is neutron irradiation. [34][35][36][37] Neutrons create primary knock-on displaced atoms in semiconductors, which produce trap states in the bandgap and degrade the electrical properties. The main mechanism for producing these displaced atoms is elastic and inelastic collisions between the incoming neutron and nuclei in the crystalline semiconductor.…”

“…The energy per cm 3 deposited through atomic displacements by neutrons is characterized by the spectral fluence φ(E) in units of n/cm 2 MeV. 36,37 The amount of non-ionizing energy loss varies greatly for different types of radiation, as shown in Fig. 1 for β-Ga 2 O 3 .…”