{"knowledge_schema": {"broad_category": "Physics \u2192 Semiconductor Physics \u2192 Charge Transport", "refinement": "This problem focuses on the conditions under which the Mott-Gurney equation accurately describes the current-voltage relationship in semiconductor devices.", "specific_scope": "The task is to evaluate the validity of the Mott-Gurney equation based on the characteristics of the semiconductor device, including carrier type, contact type, and current components.", "goal": "Identify the correct statement that accurately describes the conditions under which the Mott-Gurney equation is applicable."}, "summary": "The Mott-Gurney equation describes the current-voltage relationship in semiconductor devices under specific conditions, particularly in the space-charge-limited current regime. To determine the validity of the equation, one must consider factors such as the type of carrier (single or two-carrier), the type of contact (Schottky or Ohmic), and the presence of diffusion or drift currents. The goal is to identify which statement correctly outlines the conditions for the Mott-Gurney equation's applicability."}