Low intensity and low temperature (LILT) effects on the Upright Metamorphic Four‐Junction (UMM4J) solar cells

Upright metamorphic four junctions solar cells are evaluated under different low‐intensity and low‐temperature conditions. The efficiency findings near the Earth's orbit (1 sun, 300 K), Jupiter (0.032 sun, 123 K), and Saturn (0.01 sun, 100 K) are 26.54%, 29.68%, and 28.27%, respectively. According to the single diode model, J_sc is linear with light intensity (I), while V_oc is linear with the natural logarithm of light intensity (ln(I)). V_oc shows a linear relationship with temperature within the range of 150 to 300 K, with a temperature coefficient of ≈−7.7 mV K⁻¹. However, V_oc displays a sublinear relationship with temperatures below 150 K.