Reverse saturation current, in the context of semiconductor devices such as diodes and transistors, refers to the small leakage current that flows when the device is reverse biased. This current is primarily due to minority carriers (electrons in P-type material and holes in N-type material) crossing the depletion region under the influence of the applied reverse bias voltage. Reverse saturation current is relatively small compared to forward current but is non-zero even in ideal diodes due to thermally generated carriers.
Reverse saturation current is the term used to describe the leakage current that flows when a semiconductor device, typically a diode or transistor, is operated under reverse bias conditions. In such scenarios, the voltage applied across the device is opposite to its normal operating polarity. Despite being reverse biased, a small amount of current can still flow through the device due to thermally generated minority carriers moving across the depletion region. This phenomenon is intrinsic to semiconductor physics and is a fundamental characteristic of diodes and transistors.
Reverse current is a broader term that encompasses any current flowing through a device when it is reverse biased. It includes both the reverse saturation current, which is a small leakage current, and any additional leakage currents that may occur due to imperfections or defects in the semiconductor material or junction. Reverse current is typically unwanted in electronic circuits designed for rectification or switching applications, as it can lead to inefficiencies and affect the performance of the circuit.
Saturation current, in the context of semiconductor devices, refers to the maximum current that can flow through the device when it is forward biased and fully conducting. For example, in a bipolar junction transistor (BJT), saturation current refers to the maximum collector current that flows when the transistor is in saturation mode, where both junctions (base-emitter and base-collector) are forward biased. Saturation current is crucial for determining the operating conditions and performance characteristics of semiconductor devices in active modes of operation.
In the International System of Units (SI), reverse saturation current is typically measured in amperes (A) or milliamperes (mA) depending on the device and its application. In the General Electric (GE) system, which is less commonly used today in scientific contexts compared to SI, the unit of current would also be amperes (A) or milliamperes (mA). The measurement of reverse saturation current is essential for characterizing semiconductor devices and understanding their behavior under different biasing conditions, influencing the design and performance of electronic circuits and systems.