Physics-Informed Cross-Study Assessment of Sensitivity, Detection Limits, and Scintillation Timing in X-Ray Detectors

X-ray detector development is often discussed in terms of individual performance metrics such as effective atomic number, carrier mobility–lifetime product, sensitivity, detection limit, light yield, or scintillation decay time. In practice, however, these quantities are not independent, and their relative importance changes with detector architecture and operating regime. Here, we assembled a curated literature-derived dataset covering direct-conversion X-ray detectors and indirect scintillation-based systems and used a physics-informed cross-study analysis to examine associations among selected material, device, and performance parameters. Direct and indirect detectors occupy clearly different electronic and geometrical regimes, particularly in terms of bandgap and active-layer thickness, despite substantial overlap in absorber-related properties. For direct detectors, sensitivity and detection limit were inversely correlated at the study level (Spearman ρ = −0.842, p = 0.0022), but the performance landscape showed that high sensitivity alone does not guarantee the lowest detectable dose rate. A noise-to-signal descriptor proportional to Jdark/(S A) showed a markedly stronger relationship with the reported detection limit (ρ = 0.964, p = 7.3 × 10−6), consistent with the importance of considering background current and signal generation together, without establishing a particular noise mechanism. In contrast, grouping detectors according to the dimensionless Hecht transport parameter µτV/d2 produced no significant difference in sensitivity between transport regimes, which does not establish a transport-saturation threshold. Study-level descriptor analysis further showed that Zeff remained significantly associated with sensitivity after false discovery rate correction, whereas no individual descriptor retained statistical significance for the detection limit after correction. For scintillators, a higher light yield was accompanied by a longer decay time, while the fraction of total photons available within the first 5 ns decreased with increasing total light output. These associations illustrate the multi-parameter nature of X-ray detector performance: absorption and transport establish the available signal, whereas low-dose direct detection is increasingly governed by noise and device-level effects, and indirect detection is constrained by the competing requirements of brightness, timing, and radiation tolerance.